CA2124559A1

CA2124559A1 - Nonionic x-ray contrast agents, compositions and methods

Info

Publication number: CA2124559A1
Application number: CA002124559A
Authority: CA
Inventors: Mills Thomas Kneller; Youlin Lin; James Wheatley
Original assignee: Individual
Current assignee: Mallinckrodt Inc
Priority date: 1991-12-03
Filing date: 1992-12-02
Publication date: 1993-06-10
Also published as: JPH07501809A; EP0619744A1; AU3273993A; EP0619744A4; WO1993010825A1

Abstract

Triiodinated isophthalamide derivatives, useful as X-ray contrast agents, having at least one amide group derived from the amino-alcohol, 3-(N-2-hydroxyethyl)amino-1,2-propanediol, which provides high water solubility and low mammalian toxicity, and methods of preparing them. Methods of preparing 3-(N-2-hydroxyethyl)amino-1,2-propanediol are provided.

Description

WO ~3/lOX25 2 l 2 ~ S S 9 PCr/US92/10629 NONIONIC X-RAY CONT~ST AGEN~S, COMPOSITIONS AND METHODS

This is a continuation in part of application Serial Number 764,644, filed September 24, l99l, a division of application Serial Number 450, 693, iled December 1 3, 19 8 9 .
Field of_the Invention This invention relates ~o novel X-ray contrast agents I methods of prepariny them, radiological composi~ions containlng such agents, and method~; for X-ray visualization utilizing such compos.itions"

Nonionic contrast agents for intravascular and central nervous system visualiza~ion are complex molecule~ A~ is:known, the iodine in the molecule pro~ides opacific~tion to the~:X-rays, whiIe the remainder of the molecule provides th~ramework for transport of h~iodine atoms. Ho~ever, the structural arrangement o~
thé~mole~uIe is important in:providîng stability~:
20~ s~lubility~and biological saf~ety;~in Yarious or~gans. A
st~able ¢arbon-iodine~bon~is~achieved in most compounds by~ taching it~o an arom~ic:~nucleus. ~n enhanced: : :
degree~ of solubll:ity~as~well~as safety is:conferred on the~ma~le~ule by;the add~ition~of~suitable~s~olubil:izlng:and~
25 ~ detoxi~ying~group~. ~Forther,; nsnionic~contra~st;agents~
a~re~:~ar:~icularly desira:ble~ ompared~to c~ntempora~ry ionic : :~ ;:
age~ts~:due to:t;he ~i:nimization o~f~those pharmaco~lo~ical ffec~s ;associated:with colligative prop~rti~, e.~g~
osmolality, 30 ~ : Several~o;~ the features th~a~t are desi~able for :~
travascular and ~entral nervous system nonionic contrast ~ agents are often incompatible so that all such :~ a~ents ;~represent comp~omises . In s~arching for thé best W093/10X~5 PCr/US92/10629 212 1S~ 9 compromise, the controlling factors are pharmacological inertness, i.e., in vivo safety, and high water solubility. Thus, the ideal intr~vascular or central nervous system nonionic agent represents a compromise in an ~ttempt to obtain the following criteria: (1) maximum opacification to X rays; ~2) pharmacological inertness;
(3) high water solubility; (4) stability; (5) selective excretion; (6) low viscosity; and (7) minimal osmotic efPects.

Illustrative nonionic contrast agents include N,N'-bis(2j3-dihydroxypropyl)-5-N-(2-hydroxyethyl)glycolamido-

2,4~6-triiocloisophthalamide (Lin, U~S. Patent No.
4,396,598) and 5-N-(2,3-dihydroxypropyl)acetamido-2,4,6-triiodo-N,N'-bis(2,3-dihydroxypropyl)i50phthalamide lS (Nor~al et al., U.S. Patent No. 4,250,113 and Rakli et al. U.S. Patent No. 4,396,597).

There i5 a continuing neecl for nonivnic contrast : . agents which ~eet all or substantially all of the foregoing criteria. It is ~n object of the present :20 in~ention to provide nonionic X-ray contrast agents which ubstantially meet;these criteria. :It is a ~urther ob~ect of ~is invention to:provide nonionic X-ray contras~agents~with improved pharmacological inertness, i.e~, low toxicityp by means c~f the ~incor~pora~iorl of as h~ghly hydrophi:1ic side~ chains. It is a s~Lll further object of this invention to provide ~chemica:lly stable nonionic X-ray contrast agents having low osmolality.
Other objects and features will be in part apparent and in part pointed out herein~fter.

30 ~ Summary o the Invention Briefly, the~present invention is directed to compounds of the formula:

: ~ :

wo g~/l082s 2 1 2 ~ ~ ~ 9 PCI/U~;92/10629 COP~I

R~/N~ COR, wherein R~ is N(CH2CH2OH)CH2CHOHCH2OH, ~2 equals R~, NH2, NHCH3, NHCH2CH2OH, N ~ CH3) CH2CH20H or NHCH2CHOHCH20H; R3 equals CH3, CH2CH3, CH2C)H, C}I ~ CH3 ) OII, CH ( CH3 ~ OCH3, CHOHCH~OH, CH2OCH3, or CH2OCH2CH3; R4 equa 1 s H, CH3, CH2CH2OH, CH2CH2OCH3, CH2Cl~ HCH2OH, or CH2CHOHCH2OCH3; or R3, R4, and the 5 N
together f orm the group ( HO ) o , wherein n equals 0-3, pre~erably O or l.
;: :~
?he:present~invention is also: dire~ted to dimers of the~:~abo~e compound ~onnected~at::the 5-N~pos:ition by means 2:0;~ o~ a~:diamide, thu~s~

OC ~ H~ ~COR~

wher~in:~l and~;have the~meanings~ given above;~R5 iS
C~,~ CN2CH2OH,: CH2CHO~CH2OH, and:~H20CH3; and m eqpals~ol-4,~
:preferably~0-2 The present~;invention:is further~directed~:to~method :30 :~for~ma~ing~such;compounds: by~inoorpora:tion o~ an~amino~
::alco~ol,~ 3:-~(N-2~-hydro~yethyl~amlno-~2-prop~ediol~ and :
:methods of:~making this amino-alcohol. The inven~ion is;~ ~

,:
:: :: ~ : :

W~g~ 2~ PC~ JS9~ 629 '~ I 2 ~ ~ 5 9 also directed to radiological compositions containi~g such compou~ds and methods for utilizing such compounds in X-ray visualization.

Water solubility and safe~y of triiodinated.
aromatic compounds are obtained by attachment of suitable polar and hydrophilic side chains. 3-(N-2-Hydroxyethyl)amino-1,2-propanediol, as in the case of other amino~polyhydroxyl groups, such ~s 3-amins~
p~opanediol used for N,N'-bis(2,3-dihydroxypropyl)-5~
(2-~ydroxyethyl)glycolamido~2,4,6-triiodoisophthalamide and 5-N-(~,3-dihydroxypropyl)acetamido~Z,4,6-triiodo-N,N'-bis(2,3-dihydroxypropyl)isophthalamide and 2-amino-1,3-propanediol used for N~N~-bis(1,3~dihydroxypropyl~L~
S-~-hydroxypropionylamino-2,4,6-triiodoisophthalamide, lS providcs good water solubility and in vlvo safety for X~
ray contrast media. However, an advanta~e of:using 3-(N-2-~ydroxyethyl~amino-1,2-propanediol is to provide even hig~er hydrophiliclty for the contrast molecule due to the introduction of an additional hydroxyl group. This ~0 hi~hly h~drophilic~amino-triol can confer wat~r-: ~ solubility and:improve the safety of X ray contrast : ::media.

; Deta1led Descr~ion of the Invention In~accordance~with the present inve~tion, it has now been found~tha~ compound~ of the ~ormuIas set outabove are suitable for use as nonionic X-ray contrast qents. Mor~ specifically in the practice of~ the in~ention, the c~mpounds may be used as n~nionic X-ray :: ~ ::contras~ agents. These agents may be us~d in various radiographi~ procedures inclu~ing those involving cardiography, coronary arteriography, aorto~raphy,:
cerebr~l and peripheral angiography, arthro~raphy, ;~ intravenous pyelo~raphy and urography.

:: : :

W~93/10~25 2 1 2 ~1 5 ~, 9 PCT~US92~10629 Each of the compounds of the present invention has at least one amide group derived from the amino-alcohol, 3-(N-2-hydroxyethyl3amino-1,2-propanediol. This ~tarting material may be prepared by reacting glycidol with ethanolamine under epoxide-opening conditions or by reacting 3-chloro-1,2-propanediol with ethanolamine under secondary amine-forming conditions and neu~ralizing the hydrochloride salt ~hus formed.

Compoun~s having a 5-hydroxyacetylamino group (5-hydroxyacetamido or 5~glycolamido group~ are unstable to basic conditions and will undergo a structural reorganiz~tion [known in this case as the Smiles rearrangement) to a phenolic ether. The Smiles rearrangement products are generally insoluble in water and are not, therefore, useful as X-ray contrast agents.
In accordance with the present invention, it has been fQund that the S~iles rearrangement can be avoided when the 5-amino group is eith~r a 50methoxyacetylamino (methoxyacetamido~ or a 5 ethoxyacetylamino moiety to ; 20 : give the compounds of the present invention wherein ~3 equals CH20CH3 or:CH20CH~CH3. The resulti~g compounds do not undergo the Smiles rearrangement.

In a sec~nd, related stability enhancem~nt ~fac~ o these me~hoxylated or ethoxylated agents, U.S.
Patent No. 4,396,597 teaches that compounds with a 5-tN-hy~roxyalkyl~acetylamino] group~are unstable and undergo a base ca~alyzed cyclization and iodine elimination which renders this class of compounds less useful as X-ray contra5t media. An example of such a compound is 5-N(2,3-dihydroxypropyl)acetamido-204,6,-triiodo-N,N'-bis(2,3-dihydroxypropyl)isophthalamide. The ~597 patent further ~eaches that this problem may be overcome by utilizing a temper~ture dependent buffer. In .

W~93/10825 PCTt~S9~/~0629 2 12~S59 accorda~ce with the p~esent invention~ it has been found that the cyclization and deiodination problem may also be averted by replacing the 5-N~ hydroxyalkyl) group with 5 N~ methoxyalkyl) group. This replacement in compounds of the invention, that is wherein R4 equals CH~CH2OCH3, yields a compound that is stable to cyclization and iodine elimination at near neutral to basic pH.

Compounds of the present invention having a substituted la tam cy~lic structure at the 5 position, that is, where R3, ~ and the 5-amido are combined to form o N
(HO)~ ~
have the added ~dvantage of avoiding both types of instability, re~rran~ement and cycliza~ion~ Tha hydroxyl substitution of the lactam structure has ~he adv~ntage of increasing the water ~olubility as needed for X-ray c~ntrast compounds.

To further improve the ~smotic effects of nonlonic X-ray contrast media, the present invention also includes dimeric:compounds. Hyperosmolal ty is known to cause va cula~ pain during the injection of an X-ray contrast agent. Furthe~more, high osmolality has been 25 : shown to be an important factor in perturbat~on of the normal heart functions at the time of cardivangiography.
~:: The maln aid~a~age o~ the dimers of the present invention :
is the low osmolalit~ with concomitant low tox~city This is achieved by highly soluble dimeri~ compounds : 30 having slx iodine atoms per molecule as provided by the present in~entionO At a fixedi iodin~ concentration, these compounds exhibit si~nificantly lower osmotic e~fects~han e~uivalent monomeric agents due to reduced number of solvated particles in the solution. The WO ~9~/10~5 P~/US92/10629 2 ~ 2 ~1 5 ~ ~

dimeric compounds of the present invention provide this advantage while maintaining acceptable solubility characteristics due to the high hydrophilicity of the amine-alcohol side chains.

S In further accordance with the present invention, radiological compositiorls may be prepared containing one of the aforementioned compounds of the invention as an X-ray contrast agent together with a pharmaceu~ically acceptable r~diological vehi~le.

~O Pharmaceutically acceptable radiological vehicles include those that are suitable for injection such as aqueous buffer solutions; e.g., tris(hy~roxymethyl)amlnomethane (and it5 ~alt6), phosphate, citrateg bicarbonate~ etc., ~terile water for lS injectionl phy~iological saline~ and balanced ionic sol~tions containing chloride and/or bicarbonate salt~ of normal blood pla~ma cations such as Ca, Na, K and Mg.
: Oth~r bùffar solutions a~ described in Remington's Practic~ of Pharmacy, Eleventh Edition, for example on pag 170. T~e vehicles may contain a chelating amount, eOg. p a 5mall ~amount, c~ ethylenediamine ~:etraace~ic acid, the c:a~lcium ~ di~;od~ium 5alt, or other pharmaceu~ically acceptable ch~l~ting agent.
: ~ :

ThP concentration of the X-r;~y c:ontrast agents : ~ Z!5 of the invention in the pharmac utically accept;~ble vehic~3, for example an aqueous medium, varies with the particular f ield of use . A suf f iclent amount is present to pro-.ride satis~a~tory X-ray visualization. For example~ when using aqueous solutiorls for angiography, the cont::entratiorl of iodine is gene~ally 140-4~0 mg/ml and the dose is 25-300 ml.

WOg~/10~25 PCT/US92/10629 ~ l2 1559 The radiological compositions of the invention may b~ used in the usual way in Xray procedures. For example, in the case of selective coronary arteriography, a sufficient amount of the radivlogical composition to 5 provide adequate visualizat.ion is injected into the coronary system and then the system is scanned with a suitable device such as a fluoroscope.

Examples of the compounds of the present invention wherein R~ and R~ are the same are N,N'-bis[(2,3- ..
dihydroxypropyl~-2-hydroxyethyl]-5-acetamido-2,4,6-triiodoisophthalamide; N, N ' ~bi S ~ ~ 2, 3 -d ihydroxypropyl)-2-hydroxyethyl3-5-hydroxyacetamido-2,4,6~triiodo-isophthalamide; ~,N~`-bis~(2,3-dihydroxypropyl)-2-hydroxyethyl]~5-~2-hydroxy~propionamido~2,4,6-triiodo-~5 isophthalamide; N,N~-bisE(2,3-dihydroxyprGpyl)-2-hydroxyethylj-5-methoxyacetamido-2,4,6-triiodo-isoph~halamide; N,N'-bis~(2,3-dihydroxypropyl)-2-hydroxyethyl3-5-[N-(2-hydroxyethyl)hydroxyacetamido~
2,4,S-triiodoisop~thalamide; N,N'-bis~(2,3-dihydroxy-~;~ 20: propyl~-2-hydroxyethyl]-5~[N (2-hydroxyethyl)acetamido]-2,4,6-triio~oisophthalamide; N,N'-bis[(2,3-dihydroxy~
propyl~-2~-hydroxyet~yl]-5-~N-(2-methoxyethyl)a etamido]~
;: 2,4,6 triiodoisophthalamide; N,N'-~is[(2,3-dihydroxy-propyl)-2 hydroxyethyl3-5~(N-methyl)hydroxyacetamido~-2,4,6-t~iiodoisophthalamide; ~,N'~bis~(2,3-dihydroxy-propyl~2~hydroxyethyl~-5-[(N-mQthyl)acetamido~-2,4,6-triiodoisophthalamide; N,N'-bis[(2,3-dihydroxypropyl)-2 hydroxyethyl~-5-N~(2-hydroxybutyrolactamido)~2,4,6-triiodoisophthalamide; N,N'-bisC~2,3-dihydroxypropyl)-2 hydroxyethyl~ 5 N (S-2-hydroxybutyrolactamido)~2,4,6-triiodoisophthalamide; and 5-N-butyrolactamido-N,N'-bis~t2,3-dihydr~xypropyl)~2-hydroxy~thyl]-2,4,6-triiodoisophthalami~e.
These ~ompou~ds may all be made starting from 5-WO93/lOX25 2 ~ ~ L~ 5 c~ ~ PCT/US92~10629 amino-~,4,6-triiodoisophthaloyl chloride, which may be madP from 5-amino-2,~,6-triiodoisophthalic acid, which is disclosed in U.S~ Patent No. 4,~96/598, incorporated herein by reference. Generally, the 5-amino group may S first be substituted under amide-forming conditions to form the desired amide and the resulting compound reacted wit~ 3-(N-2-hydroxyethyl)amino-1,2-propanediol under amide7-forming conditions to add the desired ~mide t9 the 1 and 3 carbonyl groups. Examples of the compounds that may be usecl to react with the 5-am.ine are acetyl chloride, acetoxyacetyl chloride, 2-acetoxypropionyl chloride, and methoxyacetyl chloride. The acetoxy groups may later be hydrolyzed to produce a hydroxy group by various means, including acid hydrolysis or ion-exchange resins~

Secondary substitution of the S-amido group ~i.e., where ~ is other th~n hydrogen) is generally pre~erred to follow addition of the amino-alc~hol. Examples of compounds which may be used to react with the 5-a~ido group under basic, alkylating conditions are alkyl halides, for example, me~hyl halides, such~as methyl iodide, 2-haloethylacetates, such as 2-bromoethylacetate;
2-haloethano15t such~as 2-chloroethanol; and 2-haloet~yl methyl ethers, such as 2-bromoethyl methyl ether.

Th~ substitution of the 5-amino group to form the ; cycl~c butyrola~tamide is al50 generally prefer~ed ~o follow addition o the:amino-alcohol1 Substitution of the amine may;be ac~omplished by the addition, under amide ~roducing;condition~, of ~arious butyryl acid hali~es, such:as 4-chlorobutyryl chloride, 2~acetoxy-4-(methylthio)butyr~l chlorid2, or 2,4-dibromobutyryl bromid2. Use:of the latter two will result in a hydroxy-substituted l~ctamide following hydrolysis. Cyclization W~9~ 82~ PCT/US92/10629 2 1 2 ~ 55 9 1~
of the butyramide chain is caused by exposure to cyclizing conditions appropriate to the starting material. For example, when 2-chlorobutyryl chloride is used, the cyclization may be accomplished by using alkaline alcvhol mixtures, such as methanol and aqueous sodium hydroxide mixtures. WhPn 2 acetoxy-4;
(methylthiojbutyryl chloride is used, the methyl iodide of the butyramide is preferably formed first, followed by treatment with alkaline alcohol~

Prior to addition of the butyryl group it is preferred to protect the hydroxyl groups of the amides, preferably by means of acetate groups. This may be simply done by any acetate addition method under suitable protecting ronditions, such as by using acetic anhydride under ester~forming conditions, such as in the pr~sence oP a base, for example, pyridine. These protecting aae~ate groups and th~ one from 2-acetoxy-4-(methylthio)butyryl chloride, if used, can then be remo~ed by hydrolysis utilizing various conditions such a5 usin~ an aqueous ~odium hydroxide and methanol mixture.

When R2 doe5 not equal R1, a different synthetic route is preferred. The R2 substitution is preferably made Pi~st, followed by a substitution at the 5-amino 25 group. For example, the intermediate compound 5-amino-2,4,6 triiodo-3-N-methylaminocarbonylbenzoic aci~
chloride may be used to produce c~mpounds wher~in R2 equals ~HCH3~ 5qAmino-2,4,6-triiodo-3~iN (2~
hydroxyethyl)aminocarbonyl~benzoic acid or the acid chloride is used ~o produce compounds wherein R2 equals NH~H2CH2OH. In the latter ca~e, the hydroxyl group is p~eferably prvtected during later steps by means of an ace~ate group as desoribed above.

2 121~i~9 wo ~ ns2s ` Pcr/uss2/l062s The intermediate compounds may be prepared from 5-nitroisophthalic acid monomethyl ester via well-establis~ed synthetic routes. See, for example, U.S.
Patent No. 3,290,366, incorporated h~rein by reference, and European Application 0 308 364.

Examples of such compounds, wherein R2 does not equal Rl, are [N-(2~3-dihydroxypropyl)-N~(2-hydroxyethyl)]-DL-5-a-hydroxypropionylamino-2,4~6 triiodo-3-N methylaminocarbonylbenzamide, [N-(2,3 dihydroxypropyl)-N-(2-hydroxyethyl3~-S-hydroxyacetyl-amino-2,4,5 triiodo-3-N-methylaminocarbonylbenzamide, [N-(2,3-dihydroxypropyl)-N-~2-hydroxyethyl)3-DL-5-~-hydroxyproplonylamino-2,4,6-triiodo 3~N (2~
hydroxyethyl~aminocarbonylbenzamide, [N-(2,3-dihydroxypropyl)-N-(2~hydroxyethyl)]-3-N-(2-hydroxyethylaminocar~onyl)-S-hydroxyacetylamino-2,4,6-triiodobenzamide, rN-(2,3-dihydroxypropyl)-N (2-hydroxyethyl~3-DL-5-(N-methyl-~-hydroxypropionylamino)-2,4,6-triiodo-3-N-methylaminocarbonylbenzamide, ~N-(2,3-~0 dihydroxypropyl)-N-(2-hydroxyethyl)~-5-~N-methyl-2-~hydroxyacetylamino)-2,4,6-triiodo-3-N~met~ylamino-~ar~onylbenzamide, ~N-(2,3-dihydroxypropyl)~N-(2-hyd~oxye~hyl~3-D& S-(N-methyl~ hydroxypropionylamino~
2,4,~6~triiodo~3~ 2-hydr~xyethyl)aminocarbonylbenzamide, ~ ~2,3-dihydroxypropyl~-N-(2~hydroxyethyl)]-3-N~
hydroxyethylaminoca~bony~ 5-(N-methyl-2-hydrGxy-acetylamino;~2,4,6-triiodobenzamide/ ~N-(2~3 dihydroxypropyl)-N-(2-hydroxyethyl)~]-DL 5-(N-2 hydroxyethyl-~-hydroXypropionylamino):-2,4,6-triiodo-3-N-: ~30 methylaminocarbonylbenzamide, tN-(2,3-dihydroxypropyl~-N-; (2~-hydroxyethyl)] 5-~(N 2-hydroxyethyl-2-hydroxy-ace~ylamino)-2,4~6 triiodo-3 N-methylaminocarbo~yl benzamide~ [N-(2l3-dihydroxypropyl~-N (2-hydroxyethyl)~
: DL-5-(N-2-hydroxyethyl ~-hydroxypropionylamino~-2,4,6-WO~3/10825 PCT/US92/10629 2 ~ S~9 12 triiodo-3 N-(2-hydroxyethyl)aminocarbonylbenzamide~ [N-(2,3-dihydroxypropyl)-N-(2-hydroxyethyl)]-3-N-(2-hydroxyethylaminocarbonyl)-5-(N-2~hydroxyethyl-2-hydroxyacetylamino)-2,4,6~triiodobenæamide, [N-(2,3-s dihydroxypropyl)-N-(2-hydroxyethyl)~DL~5-N-butyro-lactamido-2,4,6-triiodo-3-N-methylaminocarb~nylbenzamide, ~N (2,3 dihydroxypropyl)-N-~2-hydroxyethyl)]-5~N-butyrolactamido-2,4,6-triiodo-3-N-methylamino-carbonylbenzamide, ~N-(2,3-dihydroxypropyl)-N-(2-hydroxyethyl)]~DL-5 N-bu~yrolactamido-2,4,6-triiodo-3-N~
(2-hydroxyethyl)amino~arbonylbenzamide, CN (2,3-dihydroxypropyl)-N-(2-hydroxyethyl)~-3-N (2-hydroxyethyla~inocarbonyl)-5-N~butyrolartamido-2,4,6-triiodobenzamide, [N-~2,3-dihydroxypropyl~ N-(2-hydroxyethyl)]-5 hydroxyacetylamino-2,4,6-triiodo -3-~aminocarbonylbenza~ide, [N;~(2,3~dihydroxypropyl)-N~(2-hydroxyethyl)~ -5-[(N-2-hydroxyethyl) hydroxyacetylamino3 -2,4,6-triiodo -3-aminocarbonylbenzamide, tN-(2~3-dihydroxypropyl) -N- (2-hydroxyethyl~3 -5-t(N-2,3~
dihydroxypropyl) hydroxyacetylamino~ -2,4,6-triiodo -3-amino~arbonylbenzamide, [N (2,3-dihydroxypropyl) -N- (2-hydroxyethylj] -5 acetylamin~-2,4,6-triiodo -3 amino~arbonylbenzamide, [N (2~3-dihydroxypropyl) -N- (2-hyd~oxy~thyl~J -5-[(N-2-hydroxyethyl)acetylamino]-2,4,6-triiodo -3 amInocarbonylbenzamide, and ~N- (:2 I 3-dihydroxypropyl~ ~N- (2-hydroxyethyl)]
-5-t(N 2-3-dihydroxypropyl)acetylamino] 2,4,6-triiodo 3-aminocarbony1benzamide.

~i~ Examp1es of thie dimeric compounds of the i present invent~on wherein R2 e~uals ~1 are N,N'-bis[3,5-b~s(N-2~3-dihydroxypropyl-N-2-hydroxyethylamlnocarbonyl) 2,4,6-triiodophenyl3malondiamidei N,N' biSt3,5-bis(N-2,3 dihyd~oxypropyl N-2-hydroxyethylaminocarbonyl~-2,4,6-triiodophenyl~oxamide; and N,N'-bis[3,5-bis(N~2,3-W~93/10~25 PC~/US9~/1062~
2 1 ~ ~ ~ i 9 dihydroxypropyl-N-2-hydroxyethylaminocarbonyl)-2,4,6-triiodophenyl~succinamide. These compounds may be prepared by first forming a dimer by reacting two moles of 5-amino-2,4,6-triiodoisophthaloyl chloride under amide-forming conditions wit~ o~e mole of a diacid chloride such as oxalyl chloride, malonyl chloride, or succinyl chloride. 3-(N-2-Hydroxyethyl)amino 1,2-propanediol is then reacted with the intermediate dimer to form t~ compounds of the prese~t invention.

Examples of dimeric compounds of the present invention wherein R2 does not equal R~ are N,N'-bis[3-(N-2-hydroxyet~ylaminocarbonyl)-5-(N-2,3-dihydroxypropyl~N-2-hydroxyethylaminocarbonyl)-2~4,6-triiodophenyl~-malondiamide; N,N'-bis[3-~N--2-hydroxyethylaminocarbonyl)-5-(N-2,3-dihydroxypropyl-N-2-hydrox~ethylamin~carbonyl~-2,4 f 6-triiodophenyl]-oxamide; N,N'-bis~3~N 2-hydrox~ethylaminocarbonyl~-'i (N-2,3-di~ydroxypropyl-N-2-hyd~oxyethylaminocarbonyl~-2,4,6 triiodophenyl]-succinamid~; N,N'-~ist3-tN-2,3-dihydrQxypropyl-: 20 aminocarbonyl~-5-(N-2,3--dihydroxypropyl-N-2-hyd~cxye~hylaminocarbonyl)-2,4,6:-triio~ophenyl]-oxamide;
N,N'-bis~3-(N-2,3-dihydroxypropylaminocarbonyl)~5-(Nw2,3 dihydroxypropyl-N-~2-hydroxyethylaminocarbonyl)-2,~,6-triiodophenyl~-malon~iamide; N,N'-bis[3-(N-2,3- -~:~ 25 dihydroxypropylaminocarbonyl~-5-(N-2,3-dihydroxypropyl-N-: 2Dhydroxyethylaminocarbony1)-2,4,6-triiodophenyl~-succinami~e; N,N'-dimethyl-N,;N'-~isC3-~N-2-; hyd~oxy~thylaminocarbonyl3-5-tN-2,3-dih~droxypropyl-N-2-hydroxyethylaminoCarbonyl~-2,4,6-trilodophenylJ-:: 30 malondiamide~ N,N'-dimethyl N,N'-bi~3-(N-2 hydroxyethylaminocarbonyl)-5~ 2,3-dihydroXypropyl-N-2-hydroxyethylaminocarbonyl~2,4~6-triiodophenyl]-oxamide;
N,~'-dimethyl-N,N'-bisC3-(N-2-hyd~oxyethyl~
aminocarbonyl) 5-(N-2,3-dihydroxypropyl-N-2-W~93/~OX25 P~T/U~92/10629 212~ 9 hydroxyethylaminocarbonyl)-2,4,6-triiodophenyl)-succinamide; N,N'-dimethyl-N,N'-bis[3 (N-2,3-dihydroxypropyl-aminocarbonyl~-5-~N-2,3~dihydr~xypropyl-N-2-hydroxyethylaminocarbonyl)~2,4,6-triiodophenyl~-oxamide; N,N'-dimethyl-N,N'-bis~3-(N-2,3-dihydroxy-propylaminocarbonyl)-S-(N-2,3-dihydroxypropyl-N-2-hydroxyethylaminocarbonyl)-2,4,6 triiodophenyl~
malondiamide; and N~N'-dimethyl-N t N'-bis[3-(N-2,3-dihydroxypropylaminocarbonyl)-5-~N-2,3-dihydroxypropyl-N~
2-hydroxyethylaminocarbonyl)-2,4,6-triiodophenyl]-succinamide.

These compounds are prepared by first making th@ desired R2 substltution and then forming th~ dimer by reaction with the de5ired d;~cid chloride, such as oxalyl ~5 chloride~ malonyl chloride, or su~cinyl chlo~ide. The amino-alcohol is then added under amide-forming conditions. If secondary substitution of the diamide nitrogens is desired, i.e., when Rs is other than hydroqen~ this st~p is performed last. Examples of compounds which may be used to add the de~ired substituents under ~asic, alkylating conditions are alkyl halides, for example, methyl halides, such as methyl iodIde; 2-haloethylacetates, such as 2 bromoethylacetate;
2-haloethanols, such:as 2-chloroethanol; and 2-haloethyl : ~25 meth~l ethers, suc~ as 2-bxomoethyl methyl ether.

The reactions necessary to produce the compounds of the present inventîon may be carried out at ; I any con~enient temperature and pressure, such as at atm~spheric pressu~e and ambient tempera:tures.~ It is preferred that amida~ion and alkylation reactions be performed~at such ambient temperatures. It is preferred that hyd~olysis steps be carried out ~t elevated temperatures ~o achieve a sufficient rate of hydrolysis, w~ 93/lnx2s 2 ~ 2 ~ ~.3j 9 PCT/US92/10629 such as at tempPratures between 90 and 100 C.

Purification of the compounds of the present invention is desired for their use as X-ray contrast a~ents. Purifi~ation may be by standard isolation methods, such as crystallization, or by preparative HPLC, such as by reverse-phase HPLC, or combinations of these, The following examples of the practice sf the pr2sent invention are meant to be illustr~tive and are in no way limiting the 5cope of the invention.

: ::

:: :
, ; ~ , WO~ 25 PC~'/US9~/~062g ~2'15~9 16 Preparation of N-(2,3-Dihydroxypropyl)-N-(2-hydroxyethyl)-3-N-(2,3-dihydroxypropylaminocarbonyl)-5 (hydroxyacetylamino)-2,4,6~triiodvbenzamide A. 3-N-(2,3-DihydroxYpropylaminoearbonyl)-5-acetoxyacetylamlno-2l4/6-triiodoben2~yl chl ride. To 5-acetoxyacetylamino-2,4,6-triiodoisophthaloyl chloride ~lQOg, 0.1437 moles) was added anhydrous DMAc g360mL).
The reaction mixture was cooled to 20C and then 3-amino-1,2-propanediol ~27.49g, 0.3018 moles~ as a solution in DMAc (108mL) was added at such a rate that the temperature remained below 25~C. The reaction mixture was stirred at rovm temperature for 2.5 hour~ and the reaction progress checked by TLC employing a mobile phase o~ EtOAc/CH2~0Ac (30:~0:1 v/vfv) which indicated a trace o~ st~rting material remaining. At this time the DMAc solvent was removed under h:igh vacuu~ until a thick oil was o~tained. To this oil was adAed dioxan6 ~1 L~ and the cloudy mixture:was heat~ad to 80~. A yellow oily 20: ~ impurity separated out of solution. The solution was : decanted away from the oily impurity into CH~C11~3 L) with rapid stirring. The CH2c12 slurry was cooled to lo-15C
while stirring. ~he product was c~llectad by vacuum filtration:on Wha~man ~4 filter paper, the collected soli~s were dried in a ~rced-air oven at 450C ~or 3 hours to give the de5ired product as ~ tan powder :(61 g 57% yield)~ TL~ employing a solvent system of EtOAc/CH2Cl~/~OAc ~(30:20:1 v/v) of both the mother li~uor and the dried solid product revealed only a 5ingle spot with no trace of starting material.

B. N-~2,~DihYdroxyproPyl) N-~2-hydroxyethyl~-3-N-(2 ! 3~
dihx~roxy~s~laminooarbonyl)-S-~acetvx~cetylaminoL-2,4,6-triio obenzamide. To 3-N- (2, 3-dihydr~xypropyl-' WO g3/10825 2 1 ~ 9 PCT/US9~/~06~9`

aminocarbonyl)-5-acetoxyacetylamino-2,4,6-triiodobenzoyl chloride (60 g, 0~0817 moles~ was add~d DMAc (150mL) and the mixture stirred until dissolution was complete. 3-~N-2-hydroxyethyl)amino-1,2-propanediol (8.14mL of a 41%
w/v solution in DMAc, 33.37 g (HE)APD,00245 moles) was then a~ded rapidly in one portion. 5tarting temperature was 23~C, final temperature was 240C. The addition funnel was rinsed with 30mL DMAc and this was added into the reaction mixture. The cooling bath was removed an~
the mixture was stirred at room temperature for`16 hours.
The mixture was then concentrated on a rotaYapor under high vacuum with warmin~ of the reaction flask in a 70C
water ~ath to remove DMAc which afforded the crude product a5 an oil (llSg). This product was not purified lS but was used directly in tha next reaction.

C. ~ , } Dih~r~y~d~eyll-N-(2-hydroxyethyl~-3~N (2,3 ihvdroxYPr ~Ylaminocarbonyl)~5-(hydroxyacet~lamino)-~2 :~,6-~riiodobenzamide. To N-(2 J 3-3ihydrox~propyl)~N~(2-hydroxy2th~ 3-N(2,3dihydroxypropylaminocar~ony~)-5~
: 20 ~(~acetoxyacetylamino)-2,4,6-triiodobenzamide was added deionized water (200mL) and the mixture was stirred until all~th~ oil dissolved. The~pH was ad~usted to pH~l by :
t~e~addition o~ concentrated H2S04 ~9,$g, O.lOOS moles) initia~-pH~8.54;;final pH:0~945). The~reaction~mixture~ :
, I ~
was steam dist~illed and the ~istillate collected while:
ma~nta~ning the original volume of the reacti~n mixture by periodic additlon of additional deionized~:water. The~
progre~s of the reaction was mo~nitored:~y HPLC [emplo~ing : a C18 reverse phase lO~m silica gel column employinq a mobile phase of water-acetonitrile (7~:30 v/v) at a flQw : rate of 2 mL/min,~and ~etection at 254 nm]. A~ter 6 hours of steam distillation, HPLC:analysis indicated an ~: ~ 84.5:area % f~r the desîred product. At this time an addi~ional aliquot of concentrated sulfuric acid ~3.7g, : :
: :

. .

W~93/ln8~5 PCT/US92/106~9 2 lZ 1353 1~
0.0377 moles~ was added, and steam distillation was continued for another 2 hours. The steam distillation was stopped, the solution was allowe~ to cool to room temperature, and the re~ction mixture checked by HPL~, ~hich indicated an 85.2 area % yield of the desired product. This crude material was purified as de~cribed in step D.

D. Product Purification:

D~ ioniz t on and decolorization. Xnto a 5 cm i.d.
fritted ~31ass chromat~graphy column was added IR-120H
(172mL wet volume) and IRA-68 (208mL wet volume) ion exchange resins (Rohm and Haas CompaRy). The cslumn bed wa5 topped with washed sand. The acidic solution of the crude product was eluted through the column at a fIow rate of not less than 29 mL~min. The column was rinsed with dQ~onized water unti the eluant no longer contained product. The pH of the ~luant was adjus~ed to p~4 by stirring with additional IRA-68 resin and filtration r Darco G-60 (4 grams) was adcled to the filtrate and the suspension was stirred briefl~ and then ~ ered ~filtrate pH=4.5).: The light yellow filtrate was ;~ e~aporated under high vacuum on a rotavapor;with warming of the rotary f~a5k in~a 70~C water bath to af~ord the : , crude deivnized product ~7~g)O

~:
D-~. PreParat_ye Chromatoqraph~. To the crude deionized : produ~t t75 g) was added deoinized water (91mL)~ to give ~6S% w/y so~utlon.. An M-70 stainless steel ~lumn ~ ~
~Wat~r~D Inc.~ pack~d with C-18 bonded phase silica:gel : ~was washed with 10 L of methanol and then equilibrated w~th 20 L of dei~nized water. The above solution of the :crude deio~ized~product wa5 in3ected onto ~he column and the column eluted with water at 250 mL/min. Fi~teen ' W093/10X25 2 12 ~ ~ rj 9 PCT/US~2/10629 fractions of 4L each were collected. Fractions 4 through 11 were determined to contain the desired product by analytical HPLC analysis with detection at 254 nm. These fractions were combined and concentrated under reduced pressure to a finial volume of -1 L. This solution was passed through a 0.22 ~m Millipore filter and then completely concentrated under reduced pressure to give the purified product as a white solid (41 g, 55% yield).
NMR spectral analysis of the product was consistent with the desired product contamina~ed with traces of DMAc.
The product was further purified by repeating the above preparative chromatography procedure. Thus, the above purified sample (41 g) was dissolved in deionized water (50 mL) and injected onto ~h~ above M-70 revers~ phase HPLC column which had been preequilibrated with deiQnized water. The column was elu~ed with deioni2ed water at a flow of 150 mL/min. ~ract.ions containing the purified ;' produat were combined and concentrated under reduced pressure to a v~lume o~ ~~50mL. This solution was 2~0 stirred for 1 hour~with 1.;2g of activated charcoal and :~ then filtered through a Millipore 0.22 ~m mem~rane : filter. The filtered soIution was completely : co~entrat:ed under reduced pressure to afford 29.45 g 39.~5% yield) o~ N~(2~,3-~ihydroxypropyl)-N ~2-hydroxyethyl)-3-N-(2,3-dihydroxypropylaminocarbonyl~-5- -hydroxyac~tylamino)-2~,4,6-triiodohenzamide. Mp. 2~5C
(dec.~, Anal. calcd for C~8H24I3N309: C, 26.79; H, 3.00; N/
5.21; I, 47.17. ~ound: C, 26.45; H, 3.09; N,~5.16; I, 47 . 07 . The 13~ NMR spectrum was consistent with the: ~ :
30 assigned :~tructure. LDso [i.v~ ~n mice employin~ a 35% I
(w/v) solution was determined to :be 16-17.5 gI/kg.

: : EXAMPLE 2 Preparation of N-2,3-Dihydroxypropyl-N-2-hydroxyethyl-5--~ : hydroxyacetylamino-3-(N-2-hydroxyethyl-N-:: :

: , .
. .

WO 9~S/10~'25 ~C~T/USg2/~0629 2124~59 methylaminocarbonyl)-2,4,6-triiodobenzamide A.
2~4~6-triiodobenzoic Acid. To ~ stirred solution of 5-amino-3-(N-2-acetoxyethyl-N-methylaminocarbonyl)-2,4,6-triiodobenzoic acid (203g/ 0.33 g-mole) in DMAc (385 ml) con~aining 4-dimethylaminopyridine (8.lg, 0.~66 g-mole~
is added acetic anhydride (135g, 1.3~ g-mole) at 25-350C.
Stirring is continued at room temperature for 16 hours to complete the reaction.

The solution is then evaporated under vacuum tv distill off 350 ml of the solvent to provide a thin oil. The oil is dissolved in ISO ml ~f ~Ac and the svlutlon is added slowly intv 2L of water with stirring to precipitate yellow ~olid. The resulting slurry is acidified with 150 ~S ml of 6N HCl to pH 1. The solid is collected, reslurried in 500 ml of water, treated with ~aHSO3 (20g), collected, washed three times each with 50 ml of water and dried to obtain l~Og of the desired pr~duct (~3% yield).

B. 5-Amino-3-~N-~-acetoxyethyl-N~methYlaminocarbonyl)-~
2,4.6-triiod~obenzoYl Chloride. The product of S~ep ~
(49g, 0.075 g-mole) ~nd thionyl chloride (8gg, 0.75 g-mole3 are mixed and refluxed for 4 hours. The excess ~hionyl chloride is evaporated to give a thick oil. A
mixture of THF (150 ml) and EtOAc (50 ml~ i5 added to dissolve the oil and~the resulting solution is washed twice with 10% NaCl (200 and lOO ml). After drying over ; ~ ' anhydr~us MgSb4~ the solution i~eYaporated to:dryness~o yie~d 46.2g o~ the desired product (91.7% yield)~ The product exhibited one major spot b~ TLC employing EtOAc as t~e elution solvent, The structure is confirmed by 13C
N2~

W~3~10~25 2 1~ 9 PCT/~S9~/~0629 C. 5-Acetoxyacetylamino-3-~N-2-acetoxyethyl-N-methylaminocarbonyl~2,4,6~rliodobenzoyl Chloride. To a solution of the pr~duct (4~g, 0.068 g-mole~ obtained from Step B in 100 ml of THF is added acetoxyacetyl chloride (28.1g, 0.206 g-~ole) and the solution is heated and stirred at 55C for 20 hours. The solvent is evaporated and D~Ac (50 ml) is added. Stirring and heating (60C) continue for another 16 hours to complete the reactlon.

DMAc is evaporated and THF (50 ml) is added to give a thin slurry. The slurry i5 added into a mixture of methanol ~lL~ and water (0.4L) with vigorous stlrring at lO~C to precipitate the desired product (15g, 28% yield), The struct~re is confirmed by i3c NMR. The methanol-water solution still contains the remaining product. However, no attempt is made to isolte the product.

D. 5-Acetoxyac t~laminQ-3-(N-2-acetoxyethyl-N
methylaminocarbon~J-N~2~3-dihydroxypropyl-N-~-hy~roxyethYl-2~4~6-triio~dobenzemi~de~ The product of ~tep C (14.9g, 0.02 g-mole~ is dis~sol~ed in dioxane (40 ml) and a solution of DMAc (14~5 ml) containlng 6g (0.044 g-: mol e) of 3-(N-2-hydroxyethyl)amino-1,2 propanediol i5 added. The~solution is s~lrred at room t mperat~re overnig~t ~o complete the reaction. The~solvent is then evaporated:~o provide the crude desired~product. The mat~rial is used direc~l~ in the follow.ing reactiun without further purification.

E7 N-2,3-.~hydraxy~ro~yl-N-2-hydroxyethyl-5 hydroxyacetylamin -3-(N 2-hYdroxyethyl-N-meth~laminocar~onylL-2 4,6-triiodobenzamide. The crude 30 produck from Step D is diss~lved in MeOH (100 ml) and the solution is dilu~ed with water (100 ml~. The pH of the solution is adjusted to approximately 1 wikh 1 ml of .

W09~/1OX~5 PCT/US92/10629 2~2~9 22 ~oncentrated sulfuric acid. The resulting solution i5 stirred and heated at 90~C overnight to complete the hydrolysis of the acetate groups.

The solution is passed through ion exchange resins (50 ml of IR~-68, 40 ml of IRA-458 and 50 ml of IR-120 H) and the resins washed four times with 50 ml of a l:l mixture of methanol-water. The 50lutions are combined and evaporated to provide a yellow glassy solid (13.7g; 80%
pure by HPLC). The crude product is then purified by reverse-phase preparative HPLC to provide the purified desired product.

Preparation of 5-Amino-2,4~6-triiodoisopht.haloyl chloride.

5~Amino-2,4,6-triiodoisophthalic acid (234.5 g, 0.42 g-mole) is slurried in 200 ml o~ ethylacetate at 50C.
Thio~yl chlori~e (39903 g, 243.8 ml, 3.36 g-mole~ is added dr~pwise over a ~ h~ur period. The temperature is then increased to 68C, and the contents:are stirred for 7 hour5, a~d then for an additional 16 hours at room ~: ~emperature (20~25C). EtOAc and ex~e5s thionyl chloride are partially rem~ved by vacuum distillation ~vacuum, 35C
:: :
:' pot tempe~ature) to leave a yellow paste, This paste is s~irred with 200 ml ~,1,1-trichloroethane; (TCE3 at 0-5~:
: ~5 for l hour, and collected by suction filtration while cold. The fine yellow powder is washed twice with 100 ml cold 1,l,l~TCE, filtered and dried in a vacuum d~esiccator to give ~he desired~product (12.5 g, 50% yield). The produck develops as one spot by TLc(EtoAc/MeoHlHoAc;
10j501), and its 13C nmr spectrum is consistent with the s~ruc~ure.

.

WO~/I0X2S ~ 2~5~9 PCT/US92/10629 EX~MPLE 4 Preparat i on o f N, N ' -b i s [ ( 2, 3 ~d ihydroxypropy l ~
hydroxyethyl~-5-acetamido-2,4 t 6-triiodoisophthalamide.

A. 5-Acetamido-2l4.6-triiodoisophthaloyl chlorideO 5-5 O~mino-2,4,6-triiodoisophthaloyl chloride (190 ~,0.32 g-mole~ prepared as in Example 1 is dissolved in ~75 ml o~
N,N-dimethylacetamide (DMAc) (dried over molecular sieves), and the solution i5 stlrred and cooled to 0-3C.
Acetyl chloride (75.1 g, 6~ ml, 0.96 g-mole) i5 added dropwise over a period of 100 minutes, keeping the temperature between OC and 3C. The ice bath is removed and the solution i~ stirred overnight at room temperature ~20~25C). An additional charge of acetyl chlorid (8.5 g, 0.11 g~mole) is added; and the mixture is stirred overnight ~23 hours~. The product (a creamy white sold~
precipitates during this time. The mixture is cooled to 0-5C and filtered while cold. After rinsing with three 10n-ml portions o~: hexane on the funnel, the solution is stirred with three 200-ml portions of ~old hexane for 10 :minutes each time, collected ~y suction filtration, and ~ dried in a vacuum:desiccator (183 g, 90% yield). The ;~ ~ product shows one major spot by TLC analysis.
: ~ .

..
cetamido-2,Ç,6 triiodoiso~hthalamide. A mixture o~ 5-a~e~amido-2~:~4,6-triiodoisophthaloyl chloride (92.0 g, 0.~14 g-mole~ and anhydrous Na2CO3 (38 g, 0.36 g-mole) in a fla~k rontaining 200 ml of dry DMAc îs immersed in an i~ce b~ath. At a ~emperature oP 0-5C,i 3-(N-2- ~ i hyd~oxyethyl)amino-1,2-propanedlol (48 g, 0~36 ~mole) : 30 (96 ml of a 50%:wj~ D ~ c solution) is added dropwise wit~;
~tirring over a period o~ 1 hour, keeping the t~mperature below 5C. The~mixture is stirred for 1 additlonal hour at 0-S-C, then stirred for 48 hours at room temperature W09~/1OX25 PCr/US92/10629 2 1 2 ~ ~ 5 9 ~20-25C). The mixture is filtered ~o remove the inorganic salts; the DMAc is removed by rotary evaporation (high vacuum, 80C) to leave an orange~yellsw gum (78014 g). The gum is dissolved in water to make 250 ml o solution (pH 10.5~ and passed through a bed of IR~-ll~H strong cation exchange resin (62 ml, 1.3 meq.tml).
The resin is then wa~hed with two 100 ml portions of water; the washes and the eluent are combined and evaporated to provide an off-white foam (4908 g). The pro~uct is purified by reverse-pbase preparative HPLC to give 37.5 g of a white glassy solid (a 31% yield havin~ a purity of 99.6% by HPLC). The 13C nmr spectrum i5 consistent with the structure~ [Calculated ~ comp~sition for C~2~I3N309; C: 28.76; H: 3.38; N: 5.03; I: 45.58.
Found: C: 28.31; H: 3.40; N: 5.04; I: 45.80.J The wat~r solubilit~ ~w/v) i~ 100~, the i.v. LD50 in ~ice is 13 . 8 g I/kg, th~ osmolality is:590 mOsmfKg, ~2%I.

:; : EXAMPLE 5 Preparakion of N,N'-Bis[(2,3-dihydroxyprQpyl)-2-hydroxyethyl~-5-hydroxyacetamido-2,4,6-triiodoisophthalamide.

A.~ 5-Acetoxy3~etamido-2.4~6 triiodoisophthQloy 59.6 g (~.1 g~mole~ of 5-am:ino~2,4,6-: triiodoi50phthaloyl chloride prepared as in Ex:ample 1~ is : : 25 ~dissolv~d in 100 mI of:DMAc and 2;7~3 g (0.2 ~-m~le) of :~ acetoxyacetyl chloride is added;as the~solution temperalture is maintalne~at 25-3~5Co After:~he addition, the soIu~ion i allowed to 5~ir and heated at 35-:40C for 4 hours to complete ~he reaction. The 501utio~ i~ cooled : 30 to~oom temperature and poured slowly into 1 L of cold : wa~er (O-5C) with stirring to precipitate the product.

The white solid is filtered, washed with cold water and : , ' WO ~3/10825 2 ~ 2 t~ Irj r ~ Pcr/VS92/106~9 dried, giving 6~ g (99~ yield) o~ the desired product.
The product shows one spot by TLC analysis (EtOAc~CH2Cl2;
30/20), The ~3C nmr data are consistent with the structure.

Bo 5-Acetoxyacetamido-N,N' bis~(2,3-dihydroxypropxl~-?-h~droxyethyl3-2,4,6-triiodoisophthalamide. 69 g ~0.1 g--mole) o~ 5-acetoxyacetamido-2,4,6~triiodoisophthaloyl chloride is dissolved in DMAc (140 ml~ and anhydrous Na2C03 (31.8 g, 0.3 g mole) is added. To the solution, a DMAc solution (87 ml) containing 26.2 g (0.3 g-mole) of

3~ 2-hydroxyethyl)amino-~1,2-propanediol is added. The mixture is heated and stirred at 35-4~t: until the reaction is com~leted as det:ermined by the TLC analysis (EtOAc/C}I2Cl2; 30~20) o After the: reaction, the inorganic 15 salt~ are ~iltered and the l~iltrate containing th~
d~sired product is evaporated to dryne~s to give a gum, The :gum is triturated with i.sspropyl alcohol to dis!;ol~re he excess ami~oDtriol. The clear supernatant is deca~nted and the residua:l sol id is dissolved in water 20 :(150 ml~, treat~d with Amberlite~ IR-l~OH resin and evaporated to dryness to give the desired product ~ 7:7 g, ~6% yie:Ld~

=Bisr(2,3-dihydroxypropyl)-2~hydroxyethy1]-5-hydrox~ace~amido-2,4 t ~triiodoisopbtha:lamide. 5 ?5 Acetoxyacetamid~-N,N'-bis~(2,3-dihydr~xypropyl)-2~
hydroxyethyl~-2,4,6 riiod~isophthalamide ~77 g, 0.086 g-mole~ is dissolved in 270 ml of;hot water containi:ng~s~.
g (0.08 g-mole) sulfuric acid. The solution i~ stirred and heated~at 9S-lOODC to hydrolyze the acetate~ At the end of ~he reaction, the solution is cooled~to room ~empe~ature:and deionized using an anionic ex~h~nge resin, IRA-g3 (Rohm and Haas Co.) to rem~ve sulfuric acid. The~solution is then concentrated and the crude W093/l082~ PCr/US92/~0629 ~l2~5~9 product is purified by preparative liquid chromatography to provi~e the purified desired product ~51 g; 0.06 g-mole, 70% yield~. The 13C nmr spectra are consistent with the structureO The HPLC purity is 99.1% (Cl8/ H2O/MeOH;
95/5). The water solubility (w/v) is 100%; the iv LD50 in mice is 5 g I/kg ~based on iodine content). Osmolality:
676 mOsm/kg (32% I3; viscosity: 8.2 cps (37~, 10.0 cps (25) ~32% I).

. EXAMPLE 6 Preparation of N,N'-Bis~2,3-dihydroxypropyl)-2 hydroxyet~yl~-5-(2-hydroxy~propionamido-2,4,6-triiodoisophthalamide.

This compound is prepared in the same manner:as described in Example 3 starting ~rom 5-amino-2,4~6-trilodoisQphtbaloyl chloride and (+?-2-acetoxypropionyl ~hloride. ~:

~ Preparatio~ of N,N'-Bis[~2,3-dihydroxypropyl) 2-: ; hydroxyethyl]-:5-(2~hydrgxy~p:ropionamido-2,4,6-0 ~triiodoisophthalamide,~ D and L~ optical isomers5 ~ :: :
: The D- and L- ~individual op~ical isom~ir of the title ~
compound~ is prepared in the s~me manner as described :in :~ ;
Example 4 from~5-amino-2,4,~-triiodols~phth~aloyl ~hloride n~ the D~ ~nd L opt;ical;:is~mer of 2-acetoxypropionyl ~ 25l chlorideO
: ; ::
~: EXAMPLE.8 : Preparation of N,Ni-Bis[(2,3-dihydroxypropyl)-2- :
~ydroxyethyl~-5-methoxyacetamido-2,4/6-: triiodoisophthalamide.

::: :
:: :
.

W~93/108~S 2 1 2 1 .~ ~ 9 P~/US92/~0629 A. 5-Methoxyacetamido 2,4~-triiodoisophth~loyl chloride, 5 Amino-2,4,6-triiodoisophthaloyl chloride prepared in Example l (59.6 g~ o.l g-mole) is dissolved in DMAc (lOo ml)~ The solution is cooled to 5~C and methoxyacetyl chloride ~2l.7 ~ 0.2 g-mole) is added slowly keeping the temperature at 5-lOC. When the addition is complete, the reaction mixture is allowed to warm tD room temperature and stirred until ~he reaction is complete. The solution is cooled to room te~perature and poured slowly into l L of cold water (0~5OC) with stirring to precipitate the product.

The white solid is filtered, washed with oold water and d~ied to provide the desired product.

methoxyacetamido-2~4~=~Eiiocioisophthalamide. 5-Methoxyacetamido-2,4,6-triiocloisophthaloyl chloride (56.7 g, 0.085 g-moIe):and anhydro~as Na2C03 (18 ~, 0.17 g-mole) are~ mixed in DMAc (70 ml~, A solu~ion of DMA ~57 ml) con~aining 3-(N-2-hydroxyethyl)amino-l,2-propanediol (34.~5 g, 0.255 g-mole):is added. The mixture is allowed t~ stir a~ 35 40C until the reacti~n is oomplete.: The mixture is then filtered to remove the inorganlc salts and:the ~ilt~ate containing the desired product i5 : evaporated t~ give a gum. The material is triturate~
with isopropyl alcohol ~o~dissolve ~he excess amino-: alcohol. The clear supernatant is dPcanted and the : Iresidua~isolid~ls evaporated to dryness toigive the:crud~
product. The crude product is dissolved in water and purified by revers:e-phas~ preparative HPLC to provide the ; . 3Q purified produGt.

Preparation of N jN'-Bis~(2,3~dihydroxypropyl~-2-.

WO~3/10825 PCT/US92/~0~29 212~S59 hydroxyethyl]-5-[N-(2-hydroxyethyl)hydroxyacetamidoJ-2,4 t 6-triiodoisophthalamide.

A.
dihydroxypropyl!o2-hydroxyethyl~-2~4~6-triiodoiso~hthalamide. 5-Ace~oxyacetamido-N,N'-bis[(2,3-dihydroxypropyl)-2-hydroxyethyl~-2,4,6-triiodo isoph~halamide, prepared as in Example 3, Step B, ~89 g, 0.1 g-mole) is mixed with K2C03 (2~.6 g, 0.2-g mole~ and 2-bromoethyl acetate ~33.4 g, 0.2 ~-mole) in DMAc (200 ml~. The mixture is stirred at 35-40~ until the reaction is complete (approximately 8-12 hours~. The solution is then cooled to room temperature and the inoxganic salts are filtered. The filtrate is then evaporated under vacuum at 70C to yield a thick oil. The oil i~
lS triturated with isopropyl alcohol to dissol~e the residual DMAC and bromoethyl ace~ate~ The supernatant is decanted and the residual solid is evaporated to dryness to prov~de the desired product.

B. N.NI-Bis r (2,3-dih~~Lroxy~ropyl)-2-hydroxyethyl~-5- r 2-~ ydrnxyethYl~hydroxyacetamido~ 2~.4,6-tr_iodo-:~ iso~hthalamide~ This compound is prepared from the ~; hydrolysis o the product of~Step A as described in ~xample 3, Step C.
.
EXAMPLE 10: ~ 25 Preparation of N,N'-Bis~(2,3-dihydroxypropyl3-2-hydroxyethyl;] 5-~N-(2-hydroxyethyl~acetamido]-2~4~6-triiodoisophth~lamide~

5-Acetamido N,N~ bis~2,3-dihydroxypropyl)-2-hydroxyetXyl~-2,4,~-triiodoiSophthalamide, prepared as i~
Example 2~ S~ep B, (83.5 g, Ool g-mole) is dissolved in l N NaOH (140 ml~ 0.14 g-mole3 and the solution is stirred W093/l0825 PCT/US~2/10629 2 I 2 1.~ 9 at room temperature ~or 1 hour and 2-chloroethanol (13.7 g, 0.17 g-mole) is added. The solution is stirred at 50C
for 5 hours to complete the re~ction. The solution is acidified with H2SO~ and evaporated to dryness under reduced pressure. The residue is triturated with MeOH
and the precipitated solid is filtered. The mothex liquor is concentrated under vacuum and the crude product is purified by reverse-phase (Cl8) HPLC to give the purified final procluct. The yield of this reaction and purification is 80%.

Preparation of N,N'-Bis[(2,3-dihydroxypropyl)-2-hydroxyethyl]-5-[N (2-methoxyethyl)acetamido]-2,4,6-triiodoisophthalamide.

This compound is prepared from 5-acetamido-M,N'-bis[(2~3-dihydro~ypropyl)-2-hydroxyethyl)-2,4,6-triiodo-isophthalamide, prepared as in Example 2, Step B, with 2-bromoethyl methyl ether (BrCH~CH2OCH3) in the same : manner as described ln Example 8.

Preparation:of NjN/-Bis~(2,3-dihydroxypropyl)-2-h~droxye~hyl]-5-(N-methyl)hydroxyacetamido-2,4,6-triiodoisopht~alamid~

N,N'-~is~(2,3-dlhydroxypropyl)-2-h~droxyethyl~-5-~
; 25 hydroxyacetamido-2,4,6-~riiodoisophthalamlde, prepared as in Example 3, Step C, (85.1 g, 0.1 g-mole) is dissol~ed :in 200 ml of watex and 110 ml of lN NaOH (0.11 g-mole) is added. The:solution is s~irred at room temperature for 1 hour and evaporated to dryness under vaGuum. The resi~ue ~: 30 is then dissolved in 100 ml of DMAc and the~solution is warmed to 39C. Methy~ lodide (17 g, 0.1~ g-mole) is .

:: :

W~g~/10~25 PCT/U~92/10629 21215~9 added dxopwise and the solution is stirred at 35C for 12-16 hours until the reaction is complete as monitored by HPLC. The solution is evaporated and the residue is dissolved in water. The solution is then treated with a cationic ion-exchange resin, e.g., ~mberlite~ IR-120H
(Rohm & Haas Co.~ to remove the salts. The solu~ion is evaporated and the material is purified by reverse-phase HPLC to yield the purified desired material.

_ __ Preparation of N,N'-Bis~2,3~dihydroxypropyl)-2-hydroxyethyl]-5-N-methylacetamido-2,4,6-triiodoisophthalamide.

This compound is prepared from 5-acetamido-N,N'~bis[2,3-dihydroxypropyl)-2 hydroxyethy~-2,4,6-triiodoisophthalamide in the same manner as descxibed inExa~ple 10.
-Preparation of M,N'-Bis[(2,3-dihydroxypropyl)-2-hydroxyethyl~-5-N-(2-hydroxybutyrolactamido)-2,4,6-2~0 tr1iodoisophthalamide.

: : A. ~
. S~Amino-2,4,6~triiodoisophthaloyl chlor~ide prepared as:in Example 1 (59.6 g, 0.1 ~-mole), and anhydrous Na2~O3(31.8 g, 0:.3 g-mole) are mixed in DMAc (200 ml)~ A solution of DMAc : (10~ mI) containin~ 3-(N-2-hydroxyethyl~amino-1,2-: propanediol ~40.5 g, 0.3 g-mole) is added slowly and the mixture is allowed to stir at 35-40C overni~ht. The ~: : mixture is then filtered to remove the inorganic salts.
The filt~rate is evaporated under vacuum and the gummy resldue is triturated with isopropyl alcohol to efect .

.

WO93~0B~ 212 ~ 5 5 9 PCT/US92/10629 the precipitation of the product. The solid is collected and dried to pr~vide 5-amino-~,N'-bis~2,3-dihydroxy-propyl)-2-hydroxyethyl]-2,4,6~triiodoisophthalamide.

This compound (79 g, 0~1 g-mole) is slurried in pyridine, and acetic anhydride 171.4 g, 0.7 g-mole~ is added dropwi~e with stirring and cooling so that the reaction temperature is maintained at ~30C. After the addition, the mixture is allowed to stir at room temperature overnight to complete the reaction.

The reaction solution is diluted with EtOAc (350 ml); ice water (350 ml~ is added and the mixture is stirred fsr 30 minutes~ A mixtur~ o~ cold water (350 ml) and conc. HCl (70 ml) is added and the mixture is stirred ~or 30 minutesO The layers are s~parated and the organic layer i~ collected, washed wîth diluted HCl (two x 100 m7) and 10% NaCl solution (100 ml). The organic layer is th~n dried over anhydrous Na2SO4 ~nd evaporated under reduced .
pressure to give the desired product. ~he produ t show6 ~ne spot by the analysls (EtO~c/CH2C12,30/20); HPLC
purity: >97% yield: 99 g {95%~.

: B~ 2,4-Dibromobutyryl bromide! This compound is : ~ prepared according to the general procedure in ~g _~y__ . Coll. Vol V, p. 255, incorporated herein by reference.
n a 2 L flask equipped with an addition funnel, a m~chanical stirrer, a thermomster and a reflux co~denser are placed 40 g of red p~osphorous and 300 g of butyrolact~ne. The system is connected to a gas trap ~hrough th~ condenser, The reaction mixture is cooled with an ice bath .: Bromine (188.4 mL, 584 g) is added over 35 minutes~ The reaction mixture reaches a maximum k~mperature of 54C. The reaction mix~ure iæ warmed to 70-C with a steam bat~. The remaining ~romine ~188O4 mL, .

W093tl0X25 PC~JUS9~/10629 21215~9 584 g) is added while the reaction is cooled with an ice bath to keep its temp~rature between 70 80OC. The reaction mixture is heated with a steam bath to 80~ for 3 hours. The steam bath is turned off and nitrogen is bubbled through the reaction mixture for 3.5 hours to drive out hydrogen bromide and excess bromine. A slow stream of nitrogen is bubbled through the reaction mixture over night. The reaction mixture is filtered through glass wool to remove the gummy r~sidue. It is distilled at 155-170C under vacuum (1.5 to 0.7 mm) to give g58.17 g (89% yield) of light yellow 2,4-dibromc~utyryl bromide. Its NMR spectrum is consisten~
with its structure.

C. ~~Nt-B~sf~2-acetoxyethyll_2/3-diacetox~ ropyl~-5__-(2 4-dibromobutYramldo ~2,4/6-triiodoisophthalamide.
2,4-Dibromobutyryl bromide (92 g, 0~3 g-mole) is placed into a flask equipped with a mechanical stirrer, a thermometer and a dry.ng tubP. The compound prepared in :Step A (78.5 g, 0.075 ~-mole) in DMAc (200 ml) is~added 2G :while the reac~ion:m:ixture i5 cooled to room t~mperature with~an i e bath. The mixture is stirred at room temper2ture until the reaction i5 complete. The mixture is;then pou~ed~slowly into 1 L of ice water~and the , mix~ure is stirred for~30 minutes as a solid Porm. The :25 aqueous mixture is extracted 3 times with EtOAc (S0~ ml : each).~ The combined EtOAc extracts~are washed~with water : (500~ml), saturated NaHCO3 solution (two times 20~ ml), water (400 ml) and saturated NaCl solution~l2~00 ml).l Thç~
!~ ` organic layer was dried over~anhydrous Na2SO4 and ~he : 30 solvent was~evaporated under reduced pressure:to provide ~: the crude desired~product to be used in the nex~ skep.
~: : : :

: d~hydroxy~opyll-2~hy~:xyethyl~-2,4,6~triiodo-.
.

.

WC) 93~lnx~ 2 ~ 1 5 ~ 9 Pcr/usg2~ln629 isophthalamide. Crude product prepared in Step C (94 g, O. 074 q-mole) is dissolved in 450 ml of methanol in flask equipped with a mechanic:al stirrer. Sodium hydroxide (50%) solution ~76 ml~ is diluted with 450 ml of water and added into the methanol solution with cooling (ice-hath). After the addition, the cooling is removed and the solution is stirred for 1.5 hours to complete the reaction~ (hydrolysis of the acetate and the cyclization). The reaction mixture is then acidified t~
pH 3 with hydrochloric acid. The solution is concentrated to about 400 ml and ethanol ~600 ml~ is added to precipita~e the inor~anic salts. The salts are filtered off and the filtrate i5 evaporated to dryness under reduce~ pressure ~o provide the crude product. The crude product is dissol~ed in water (45 g in S0 ml) and purified by pr~p HPLC to giv~3 28 g of purified de~ired product (40% yield)~

E.~ N,N' isr2~3-dihvdroxypropvl)-2-hydroxyethyll-5-N-(-2-: hydroxybutyrolactamido~-2 !4.~ 6-triiodoisophthalamide. The compound prepared in Step D ~28 g, 0.03 g-mole), di~tilled ethanol 1500 ml:) and potassium acetate (11.8 g, 0.12 g-~mole) are:mixed in a ? L ~lask equipped with a mechanical stirrer, a reflux conden5er and a thermometer.
, ~
~ The mixture is refluxed until the reaction i~s c~omplete.
: 25 The solvent is~removed under ~acuum and a solid is ~: ~ obtained, The solid is dissolved in water ~200 mlj and the solution i~ treated with 150 g of pre-washed mixed-~ed ion-exchange resins. After stirring for 15 minutes~, the resins are filtered off and the solution is .
: 30 ~vaporated under vacuum to ~ive a foamy s~lid of crude product. The material is dissolved in water ~40 ml) and puri~ed by preparative ffPLC to ~ive 8 g of the purified product as an overalI 32% yield.

, W093/~0~2~ PC~/US92/10629 21~4559 Preparation of N,N'-Bis[~2,3-dihydroxypropyl~-2-hydroxyethyl]-5-N-(S-2-hydroxybutyrolactamido~-2,4,6-triiodoisophthalamide.

A. DL-2-Acetoxy-4-(methylthio)butyric acid. Calcium 2-hydroxy-4-(methylthio)~utyrate (33.8 g, 0~1 g-mole) and acetyl chloride (110 g) are refluxed in a 250 ml r~und-bottom flask for 2.5 hours. The mixture is evaporated to a syrup and treated with 150 ml acetone. The brown mixture is stirred for 30 minutes, filtered, and th~
filtr~te evaporated to dryness to give 37 g, g~.4% of brown viscous oil which is identified by TLC and nmr.

B. Resol.ution of DL-2-Acetoxy~4-(meth lthio)butyric ~ o Resolution is a~complished with brucine. Thus, a lS solutlon of the mixed isomers 486 g ~2.53 mol) in 500 ml ::~ ethanol, is filtered in a 12;L resin pot and treated with ~: a hot ~ ered solution of br.ucine, 1 kg, (2.53 mol, Sigma Chemical) in~3 L of ethanol. The precipita~e : : formed is left~overnight at rosm temperature,~iltered, 20~washed With 2 L of et~anol~ and 1 L of ether to yield 900 g~mate~ial.~ This:is crystallized from 6 L:of ethanol to give~640 g sol:id, m.p. 184-186C, and then recrystalli2ed ; : ance:more from ethanol,-6L, to~give 570 g 501:id, 38.3%,: :
; m.p. 185-187-C,~[~]:~-31 (1% H~0).

The free acid is~released from~the;brucine~salt by~
dissolving 570 9 of t~ ~olld obtained above in 5:.~ L
wa~er in a 12 ~ resin po~. This is treated with oncentrated~HCl to ~pN 0.7 (200 ml)~,~and the pale brown ~ so~ution is~extrac~ed twice with 2.5 L ethyl ace~ate.
; 30 The extrac~ is washed with water,:three times 300 ml, : :d~ied:o~er ~nhydrous~sodlum sulfate, ~vaporated ~o ~ dryness to ~g~ve brown thick oil, 182.2 ~, 97.8t : ~ ' : : ~::

WO 93/lOX~ 2 :1~ 15 ~ 9 PCr/US~2/10~2~

33.78 ~0.1258 g in lO ml CHCl3).

C. Verification of Optical Purity. Tl~is preparation is made in order to verify optical purity of the above compound as generally disclosed at Angew. Che. Int. Ed.
1~. 7~7 (1979~; and J. Am. Chem. Soc. 78, 2429 (1956), incorporate:l herein by reference.

L-2-Hydroxy-4 ~methYlthio~ butyric acld and acetylatlon.
In a 1 ~, 3-necked f lask is dissolved L-2-~mino-4 ~
(methylthio) butyric acid ( 14 . 9 g, O . 1 g mole~ in aque :ius lû H2SO4 solution (~O m~) and cooled to -5C. This is treated with a solution of NaNO2 in 30 ml water. The mixture is stirred overnight at room temperature and extracted with I hre~ times 100 ml ether, dried oYer anhydrous N~2SO" and evaporated tv dryness to give an oi1, 1 . 4 g 9. 3~6 . TLC
î5 shows onQ major spot and IR is in agreement with the stru~ure~. Acetylation of t~e compour~d (l. 5 g, O. Ol mol ) is carried o~lt with acetyl chloride (O. 07 mol , 6. 5 ml~;
the mixture was ref luxed ~Eor 1 hour, evaporated to dryness and the resldue dissolved in CHCl3. This is extracted three times with 30 ml NaHCO3 ~;olution (5%), washed~ twice with 3û ml CHC13, filtered and :acidified with conc:entrated HCl ~pH 1). The precipitated oil is extrac:ted with chloroform, washed with 30 ml water, dried over anhydrous Na2SO4 arld e~raporaked to dryness to give browrl oil, 1.76 g (91.6%).

The brucine~ sa~lt is prepared by dissolving 1.1 ~ (O.0057 ml) of th~ abc)ve materi~l L-2~acetoxy-4- (methylthio) -butyric acid, in ~0 ml EtOH and treatment with a hot filtered solution of brucirle (O. 0057 mol, 2 . 26 ~ in 30 ethanol" 20 ml)~ The salt obtained is filtered and recrystalli~ed from ethanol (40 ml) three times to obtain pure 5alt, m.p. ~84 186~C ~3 ~31~ (1% H20), identical in WO~3/lO~S P~/US92/10629 212 1~9 m.p., mixed m.p. ~undepressed), and optical rotation to compound prepared in steps A and B~

D. L-2-Acetoxy-4-~ethylthio!butyr~l chlorid~e. In a 1 L, 3-necked flask is dissolved 173 g of compound prepare~
in (Step B) in S00 ml CH2C12, cooled in ice-methanol bath and treated with SOC12 (120 g) followed by 3 ml ~MF. The mixture is stirred overnight at room temperature. The solvent is d stilled and the residue purified by distillation at 84-86C (0.1-0.05 mm Hg~ to give pale yellow oil 157 g~ ~3~. IR ~nd n~r data are consist~nt with the structure for the desired acid chloride~

E. N~N'-Bis~2-AcetoxYethyl ~I=diA95~yn~e~vl1-~-N-5-2-acetox~-4 _ethylthio _tyramido)3-2j4.~6-triiodoiso-~L_hala ide. S-Amino-N,N'-bis~2-acetoxyethyl)~2,3~
diacetoxypropyl~3-2:,4,6-triiodoiSophthalamide, prepared a~ in Example 12, Step A, (200 g, 0.2 g-mole) ~s : ~ dissolved in DMAc (175 ml~ and c~oled in ice-m~thanol bath and treated with the acid chloride prepared in Step : :~ D (B:4~2 g, 0.4 g-mole) in 84 ml DMAc. The solution is ~st~irred at room~temperature overni~ht an~:th~n poured ~: over a solution of sodium bicarb~nate ($0,4~g, 0.6 g- :
mole) in ~50 m1 water and flltered. The sol:id is washed ,: ~ith 100 ml w~t~r twlce and dried to giYe a glassy materia~ of:the desired com~ound (24~ gj 99% yield).

: 25~ F. N,N'~i~L2-Acetoxvethvl-2.3-diaceto~ypr~Ryl]-5-N-(S-2-acetoxY-~ methylthiobutYramido~-2~4,6 , ~ odide. ~ sol:u~ion of th~
compou~d prepared in~Step:~E ~23~ ~, 0.19 g-mole) in ~MF
g475 ml) is~ stirred wi~h methyl iodide (165 g, 11.6 y-30 mole) at room~ t~emperature overni~ht. The mix'cure is : evaporated to drynes~ and the residue ~riturated withthree times 1 h ether. The residue is dissolved in :~: ~: ~ :: :
: :

.

W~3/10825 2 ~ 2 ~ ~ r3 9 Pcr/usg~/lo62g acetone (170 ml) and the product is precipitated with the treatment of cold ether. The crystals are filtered/
washed with ether to obtain a nearly quantitative yield of the desired compound (255 g).

Go N,N'-Bis~(2,3-D.i y~roxypropyl)-2-hydroxyethylL-5-N-S-2-hYdroxYbutYrolactamidol-2~4~6-triiodoisophthalamide.
A solution of the compound prepared in Step F ~136 g, 0.1 g-~ole) in 500 ml of MeOH and NaOH solution (80 g in 640 ml water) are mixed w~ile cooling with ice-water. The mixture is stirred at room temperature overnight and then treated with 65 ml of AcOH. Methanol is r~moved under reduced pressure and the solution i5 treated with mix~d-bed ion-exchange resins. The 501ution is filtered and ~oncentrated to provide th~ c:rude product. The crude product is dissolved in water and purified by prep~rati~e HPLC (~, wa~er as the mobile phase) to provide the purified material.
:~ :
EXAMF'LE 16 :: .
~: Preparation of 5-N-Butyrolactamido-N,N'-bis~(2,3-dihydroxypropyl)-2-hydroxyethyl] 2,4,6 ~riiodo-isophthalamide.

~ ~ :
. N~N'-Bis~(2-acetoxyethyl~-2~3-diacetoxy~ropyll-5-~4-. In a lask e~uipped~with a~mechanica~ ~tirrer, dropping : 25 ~funn~l, th:ermometer and dr~ing tube, 5-amino-N,N' bis~(2-acetoxyethyl)(~,3-diacetoxypropy~ 2,4,~-triiod~isophthalamide, prep~red as in Example 12, Step ~, : : (48 g, 0.046 g-mole) is d1ssolved in DMAc (120 ml)~ The solution is cooled to 15C and 4-chlorobutyryl chloride ~13 g, 0.~92 g-mole) is added slowly with stirriny. The : reac~ion solution is ~sn stirred at room temperature until the reaction is completed as determined by tlc~

.

.

WO 93/ 1t~25 PCI /l~S~2/10629 212 1~i9 3~
The solution is poured into 1 L of ice-water with stirring. A gummy material precipitates. After stirring for 10 minutes, EtOAc (350 ml plus 150 ml twice) is added to dissolve the gum and extract the solution. The 5 combirled EtOAc solution is washed with water (200 ml), Sg6 NaHCO3 (two times 200 ml), saturated NaCl solution (two times 150 ml), dried over anhydrous Na25O4 (100 gj and evaporated to give a crude solid product. Witho~t further purification, the crude product is utilized in the following step.

B. 5~N-Butyrolactamido-N.N' ~ ~l s f L 2. 3 ~d ihydroxyE~
2~4 t 6-triiodoisoPhthalamlde~ The crude compound prepared in Step A (18.4 g, 0.016 g-mole) is suspended in MeOH
(100 ml) in a flask e~ui~ped with a mechanical stirrer, an addition funnel and a thermometer. Th~ ~uspension is c:ooled to 10~C ~nd NaOH solution ~98 ml of 1 N solution) is added slowly 50 the temperature i~ maintained at 10-20DC. When 25 ml o~ NaOH soluti~n is added, ~he suspension became a clear solution. After the addition, ~:~ 20 the cooling ~ice-bath) is removed and the solution is ~tirred at room tempera~ure o~ernight.

The solution lS stirred with AmberIite IR-120H resin (120 ml) ~or 2 hours and filtered. The filtrate is evaporated to dryness:to give the crude de5ired produ~t at a quantitatiYe yield~ The~purification of the product is :: c~rried out by preparative HPLC using C~ coIumn an~
H~O/MeOH as the mobile pha5e. The elutions containing the desired product are combined and evaporated to dryness to : provide the purified product (8.2 g, 60~ yield~).

3~ EXAMPLE 17 Preparat.ion of tN-~2,3-dihydroxypropyl) N-(2 hydroxyethyl]-DL-S-~-hydrOXYpropionylamino-2,4,6 triiodo-W093/10825 % l 21~ ~ 3 9 PCT/US92/10629 3-N-methylaminocarbonylbenzamide~

~ DL-5-~-Acetoxypro~ionylamino-2~4,6~triiodo-3-N-methylaminocarbonylbenzoyl chloride~ 5-Amino~2,4/6-triiodo 3-N~methylaminocarbonylbenzoyl chloride (59 g, 0.1 g-mole) is slurried in DMAc (110 ml) a~ 35-40C. DL
2-Acetoxypropionyl chloride ~30.2 g, 0.2 g-mole) is added dropwise keeping the temperature at 40048~C. The 5~ urry is stirred at 40C for 30 minutes, turning into a cleax brown solution. APter stirring overnlght at 40C, HPLC
analysis indicates complete reaction~ The solution is slowly poured into 1.1 L of cold water ~0-~5C) with stirring. A creamy, white solid precipitates. It i5 collected, washed three times with 50 ml water, and dried to give the desired product (62.4 g, 88.6% yield) as 15 conf irmed by Tl,C and nmr .
.
~ 5~ çetoxY~oPionylamlno- r~- (2~3_dihydr~xx~
prolpylL-N-~2-hy~roxyethyl~l-2~4.6-triio~c~
:: meth~l~minocarbonY-lbenzam-lde~ The compound prepared in Step A (60 g, 0.085 g-mole) is added t~ a mixture of 3-(N-2-hydroxyethyl)amlno-1,2 propanediol dissolved in DM~c (23 gt 0.17 g~mole, in 56.4 ml solution, 40.87% w/v), ~:~ addi~ional DMAc (70 ml3 and sodium carbonate (18 g, 0.17 g-mole) at ~CC~ The mixture is:~stirred at room ~ temperature~for 20 hour5, then warmed to 40C for 5 hours, and again stirred overnight at room temperature. The mix~ur~ is filtered and the ~olid collected and washed ,twire With 50 ml DMAc. The filt~ate and washes are combined and evaporated to give a thick oil ~105.8 g).
The ~il is triturated with 200 ml isopropyl al~ohol, 30 yielding some solid and again with 700 ml acetone, yielding more sol id . The supernatant is decanted and the solid washed wlth 200 ml acetolle. The acetone is decanted and thie solid evaporated to dryness, yielding 32 ' WO93Jl0825 PCT/US92/1~629 2 l ~ S 9 q of crude, desired product. The combined decantations, isopropyl alcohol and acetone, are evaporated to yield a thick oil, which when triturated with 100 ml acetone yields a gummy solid. The solid is dried, yielding 44 g crude product, for a combined yield of 76 g.

c . r N-(2,3 dihydr-oxyE~opyl)-N-(2-hydrox~ethyl~-DL~5 hydroxy~ropionylamino-2 4,6-triiQdo-3-N-methylamino carbonvllbenzam.ide. The crude product prepared in Step B
~theoretically 0.085 g-mole) is dissolved in 300 ml water 10 (pH 9.2). Conc. H2S04 ~5 ml) is added to adjust the pH to 1. The solution i5 refluxed for 7 hour5 and then evaporatecl to dryness. The gummy solid remaining is dissol~ed in 300 m~ water and the solution is stirFed at lOO~C oYernight~ HPLC analysis showed approx. 80% purity.
The solution is then tréated with ion exchan~e resins IRA 68, IRA-458, and IR~120 H, loo ml each, and the resins are washed four times each with 100 ml water. The : washings and solution are combined ~nd evaporated to ~;~ dryness giviDg a ;yellow glassy soli~ (48 g, 83.5% purej .
The crude product is then purified by reverse-phase : preparative HPLC to yleld 34 g. The struc~ure was verified by nmr. The produc~ is 100% water soluble~ The i.v. LD50 in mice:is 13.1 g I/kg. Osmolality: 506 :~ mOsm/k~ (32%:I); viscosity: 4.9 cps (37), B.l cps (25) ;~ 25 ~32~ I).

;~ EXAMP~E lB
Preparati~n of ~N~t2,3-dihydroxypropyl)-N-(2-hydroxyethyl)~-5-hydroXyacetylaminO-2~4,6-triiodo-3-N-~: me~hylaminocarbonylbenzamide.
:~ ::
A~ 5-Acetoxya~etylamino-2 4.6-triiodo 3-N- ~
me hylaminocarbon lbenzoYl chloride. S Amino-2,4 t 6-triiodo-3-N-methylaminocarbonylbenZoyl chloride (61 g, WO (3~/ 10825 i~cr/us92/l062g 212~ii59 0.1033 g-mole) is added to DMAc (100 ml~ with stirring and heated to 30C. Acetoxyacetyl chloride is added slowly with stirring. A~ter stirring at 40C for 4 hours and overnight at room temperature, the product completely solidifies from the solution. Tetrahy~rofuran (200 ml) is added and the slurry stirred for 1 hour at room temperature. The white solid is filtered, washed three times with THF (30-40 ml) and dried under va~uum at 50C
to produce the crudeO desired product.

B. 5-Acetoxyacetylamino-~N-(2l3-dlhydr~xypropyl)~ 2-hydrox~eth~ ,4,6-triiodo-3-N-methylam~lL_ a~ cy~
Li~. The crude product oP Step A (theoretically 0.1033 g-mole) is added to a mixture of 3-(N~2- ;
hydroxyet~yl~amino-1,2-propanediol (28 g dissolved in 110 mI DMAc) and sodium bicarbonate (17~7 g, 0021 g~mol~) with ~tirring and heating to 55~C. Carbon dioxide e~olution occurs~ After stîrring at 55-60C for five hours, the solu~ion is allowed to stir overnigh~ at rvom temperature and filtered. The solid is washed three times with 50 ml methanol, and the washings are combined with ~e filtrate. ~The comb~ned solutlon is evaporat~d under vacuum a~ 70C yielding a thick oil. The oil is ~;~ : triturat~d with 500 ml ~isopropyl alcohol at 6SC for 30 minu~e~; an~l ~then allowed to co~l. The supe~natant is 2S de:canted. The residue is again triturated with 350 ml :isoprvpyl al~ohol and then allowed to cool. The s~pernatant is dec~nted and the residue evaporated to ryness under ~vacuum at 75C yielding the desired produc~
(57 g, 70% :yield), confirmed by nmr.

30 C. t~ ~ihydro~ro-p~L2-hydr~hy~ 5-h~dro~y~c: t~l. amino-~bony~benzamide. The product of Step B is hydrolyzed and purified as in ~xample 15, Step C, yielding 10.~ g, g9.8%

W0~3/lOX2S PCT/USg2/10~2~

5 5 ~
~2 pure. However, the solubility in water ~wJv) was found to be less than 25%.

Preparation of [N-(2,3-dihydroxypropyl)-N-(2~hydroxy-ethyl)~-5-[~hydroxyacetyl)(2-hydroxyethyl)aminoJ~2,4,6-triiodo-3-N-methylaminocarbonylbenzamide.

The title compound i~ prepared by hydrolysis of ~-(2,3-dihydroxypropyl)-N~(2-hydroxyethyl)~-5-t~acetoxyacetyl~(2-aCetoxyethyl)amino]~2,4,6-t~iiodo-3-N-methylaminocarbonylbenzamide by ~ procedure similar ~o~he hydrolysi5 o~ Example 15~-Step C. The diacetat~ is prepared by reacting 5-acetoxyacetylamino-[~ (2,3-dihydroxypropy~ N-(2-hydrox~et~yl)~ 2~4,6-triiod~o-3-N
m~thylaminocarbonylbenzamide (prepared as in Example 16, Steps A and B) with 2-bromoel-hylacetate in DMSO in the pr~sPnce of a base such a5 potassium~carbonate~

.EXAMPLE 20 Preparation of ~N-(2,3-dihydroxypropylt-N-(2 hydroxye~hyl)~ (2-hydroxy~ace~yl)amino-2,4,6-triiodo-3-:
2~0~ N-(2-hyd~oxyethyl)aminocarbonylbenzamide.

3-r~L2-p~cetoxyethvlLaminocarborlvl3 -5-amlno-2,~ 4 ~ s=
tr~iod be~zoic acid. To a stirred solution of:~5-amino-2,4,6-triiodo-3-N~ hydro~xyethyl~aminocarbony~lbenzoic acid~ I07.~4 g, 0.17~ ~-mole3 in anhydrous~DM~c~(l00 ml)~
25 l c~ntaining,a catalytic amount: of,4-dimethylaminopyridine 600 mg, 5:mmol:es3 is added~ace~ic anhydride (~olO g~
: ~ : 0.28~ mole,:~ equiv~ dropwise over 20 minutes at~
:~ : room~temperature. Stirring i5 continued at rvo~
temperature for 16 hours and then 200 ml water is added 30~ with vi~o~us stirring. The resul~inq suspension is ~ ~filtered, and~the ~ollected solids washed with 100 ml , ' :

W(~3/10825 PCTt~S92/1~629 ~ ~2 1~r 9 water and dried in a vacuum oven (70C, 140 mm ~g) for 24 hours to yield 98.23 g ~86% yield~ desired product. The product exhibit5 one spot by tlc employing a solvent system of ethyl acetate/methanol (95:5, v/v). IH and ~3C
nmr spectra are consistent with the assigned structure.

B. 3-U~-(2-Acetoxyethyl~aminocarbonyl~-5-amino-2,4 6-t.rii obenzoyl chloride. To the product of Step ~ (75.0 g, 0.117 g-mole) is added thionyl chloride (2Q7.9 g, 1.75 g-mole, 15 equiv.~ with stirring at room temperature.
10 The resulting solution is heated to reflux with stirring for 3 hours. Excess thionyl chloride is re~oved by distillation under reduced pressure, partly as an ~æeotrope with THF (200 ml)0 The residue is taken up in methylen~ chloride (1 L~ and washed with water (~50 ml~, saturated aqueous sodium ~ic:arbonate solution (~50 ml), and saturated aqueous sodium ~hloride 501u~ion (lQ0 ml3.
The organic solution is s~parated, dried over anhydrous sodium sul~ate, filtered, an~ concentr~ted under vacuum a~yield the desired:product (74.25 g, 96% yield). The product e~hib~ited one spot by tlc~mployin~ a solvent system of ethyl acetate/hexane (70:30 vJv~. IH and 13C nmr spectra ar~ c~onsistent with the:structure.

C. 5-Ace~toxyace~ylamino-3-N-(2-acetoxyethyl)amino~
ç3~ c~L=~ 6-trii~odobenzoyl~chloride~ To a- solution of ~the~product of Step B (~0 g,~ 0.091 g-mole~) in DMAc (60 ml) is added ac~toxyacetyl chlorid~ (24 ~ 73 g, 0~ ~8 g- ~ :
mole, 2 ~lequiv.~j with stirring over 20 minutes at ~oom temperaLture. Stirring is con~inued: at ~oom temperature : fcr 16 hours an~: the reaction mixture then added to 30 :Yi~vrously~ ~tirred ic cold water.: The resulting s~l:id produc~ is~:collected by va uu~ filtration and dried in a vacuum oven to yield 66.9~ g (96%~ ~ield~ of the desired ~ ~ ~ : product, conf irmed by ~lc and nmr .
: ~ ::

WO(~3/lOX25 P~T/US92/1~29 2 :~2~3 ~4 D. [N-(2,3-~ihYdroxypropyl)-N~12-hydroxyethyl~1-5 (acetoxyacQtylamino~-2.4,6 triiodo-3-N-(acetoxyeth~
aminocarbonylbenzamide. To a solution of the product of Step C (66.65 g, 0.087 g-mole) in DMAc (60 ml) containin~
anhydr~us sodium carbonate (9.22 g, 0.087 y~mole, 1 equiv.) is added 3-(N-2-hydroxyethyl)amin~-1,2-propanediol (43.5 ml of a 41% w/v solution in DMAc, 1.5 equiv.) with stirring at room temperatur~ under an atmosphere of dry nitroge~ After stirrin~ at room temperature for 16 hours~ the mixture is filtered through celite to remove inorganic sa~ts and then distilled under high v~cuum. This yields 102.8 g of crude product.

Eo rN-(2~3-Dihydroxvpro~yl)-N-(2-hydroxyethyl3~5-(2-hy~Lrox~acetYl2amin~-2~4~6-triiodo 3-N-~2-hydroxyethyl)aminocarbonYlberlzamide. The crude diacetateproduct of S~ep D is d~issolved in methanol (90 ml) and w~er (90 mll is added. The pH is adjusted to 1 with sulfu~ic acid, and the mixture is stirred and heated to reflux f or 2 h~urs . The mixture is then concientrated by :distillation and purified by passing it through ion-excha~ye resins~and ~y preparative HPLC, yielding 25.77 g of 98% pure product as confirmed by HPLC, tlc, and nmr.
: : The product .is lOQ~ w/v water-soluble. Osmolality: 597 mOsm/~g ~3~ , viscosity: 5.3 cps (37), 7.4 ~p5 ~~
(32% X~; the i.v. LD50 in mic~ is 20.6 gI/kg.

Preparation of ~N-(2,3-dihydroxypropyl~ N-~2~ , !
hydroxyethy})~-3-N~ hydroxyethyl)aminocarbonyl-~L-5-~-hydroxypropionylamino-2,4,6-~riiodobenzamide.

3Q AS in Example 18, the title compoun~ is prepared stepwi~e by reac~ing the product of Example 18, Step B with (~)~2-acetoxypropionyl ch].oride, as in Step C an~ completing ~0~3/~08~5 2 1 2~ ~ 3 9 PCr/US92/10629 the synthesis.

~ XAMPLE 22 Preparation of [N-(2,3-dihydroxypropyl)-N-(2-hydroxyethyl~]-5-N-(2-hydroxybutyrolactamido)-2,4,6 triiodo-3 N-methylaminocarbonylbenzamide.

As in Exampl~ 12, the title compound i5 prepared stepwise by first react~ng 5~amino-2,4,6-triiodQ~3-N-methylaminocarbonyl~enzoyl chloride wi~h 3-~N-2-hydroxyethyl)am;.no-1, 2-propanediol dissolv~d in DMAc in the presence of sodium carbonat2. The product, 5-amino-[~-~2,3-dihydroxypropyl) N-~2-hydroxyethyl~-2,4,6-triiodo-3~N-methylaminocarbonylbenZamide, i~ reacted with acetic: anhydride in the presenc~ of pyridine to produce the triacetate, [N-~2~acetoxyethyl)-N-(2:03- :
15~ :diace~oxypropyl)3-5-amino-:,4,6-triiodo-3-N-~ethylaminocarbonylbenzamide. This compound is then reac~ed ~it~ 2j4-dibrom~butyryl bromide,~prepared as in Example 12, Step B, and the product is then cyclized, ~: : : hydrolyzed:, and puriied~as in:Example 12, steps D and E
20:~to:produce:the;f:inal produ~t. ~ ~

E ~MPLE 23 ~ ~ :
Prepara~ion:of ~N-~2/3-dihydroxypropyl)-N-(2 hydroxyeth~ 5~N-(2-hydro~ybutyrolactamido)-2,4,6-~
triiodo-3~ 2-hydroxye~hyl~am~inocar~onyl~benzamide.:

25;:1 The title :compound:is prepared as in Examples 1~ a~nd l9 starting ~rom~3-N-(2-acetoXyethyl)~aminocarbonyl-5-amino~
,4,6 triiodobenzoyl chloride~ :

EX~MPL 24 Prepara~:ion of N,N'-bis[3,5-bis(N-2~,3-dihydroxypropyl-N-~: : 30 2-hydroxyethyl)ami~oearbonyl]-2:,4,6-triiodophenyl~-W~93/l()X~5 PCT/US92/10629 212~1~5~

malondiamide.

A. N.N'=bis~3~5-bis~chlorocarbonyl~ 4,6-triiodoPhenyl~-malondiamide. 5-Amino-2,4,6-triiodoisophthaloyl chloride ~59.58 g, 0.1 g-mole) is dissolved in 130 ml dioxane (dried ovPr molecular sieves). The solution is heated to 90~C and stirred while malonyl chloride (8.$ g~ 0.06 g-mole) is added dropwise.
The mixture was stirred at 90C for 3 hours. A pas~y pre~ipitate forms. The solid is filtered, washed three 10 times with 25 ml dioxane on the filter, suction-dried and then vacuum dried at 60DC to yield the desired product (51,4 g, 81~ yield~. The structure of the dimer was ~onfirmed by nmr.

B. N,~'-Bis~3,5~bisfN-2,3~dihydroxyproF,yl-N-2 hydroxyethylaminocarbonyl)-2 4 r fi-tr _odophenyl malondiamide The product of Step A ~S0 ~/ 0~04 q-mole~
is added slowly to a mixtu~e of 3~(N-~-hydroxyethyl3amino-1,2-propanediol ~32.4 g, 0.24 g-mole) : dissolved in D~ c (115 ml) and sodium carbonate (17 g, 2~ 0.16 g-mole), with stirring. ~fter 7 hours stirring at ~ room temperature, the:reaction is complete as determined :~ ~ : by HPLC. The reaction mixture is diIuted with 200 ml : .
DMAc and filtered to remove the salts. Th~ clear filtrate is evaporated to drynes~s yielding a clear yellow gummy solid (86.5 g). The solid i5 triturated wi~h 50 m~
: isop~opanol a~ 60C for 10 mi~utes. Af~er standing ,~ I overnight the supexnatant is decanted and the solid e~aporated to dryne s. The solid is dlssolved in 150 ml w ter at 60 65C y~elding a clear solution, p~ 10. The solu~ion is stirred with Amberlite IR-120 plus H resin for 30 minutes~(pH 1~2) and filtered. The filtr~te is evaporated to dryness to ~ive the crude desired product (61.4 g, g5% purity by HPL~). The crude product is W09~/ln825 212 ~ ~3'3 9 PCT/~'fS92J10629 puri~ied by preparative reverse-phfase HPLC, yielding 37 q ~56% yield) having 98% purity. The compound is 100%
(w/Y) water ~oluble. ~smolality: 213 mOsm/kg (32~ I), 191 mOsm/kg (28~ I3; viscosity: 18.8 cps (37, 32% I), 1~.4 cps (37, 28~ I~; the i.v. LD50 in mice: 17.5 gI/kg.

Preparation o~ N,N'-bis~3,5-bis(N-2,3-dihydroxypropyl-N
2~hydroxyethyl)aminocarbonyl3-2~4ff~ 6-triiodophenyl]
oxamide.

This compofund is prepared as in Example 22 using oxalyl chloride in place o~ malonyl chloride.

EXAMF'LE 26 Preparation of N,N'-Bis[3~5-bis(N-2,3-dihydroxypropyl-N-2 hydroxyethylaminocarbonyl)~-2,4,6-triiodsphenyl~-succinamide.
: : :
This compound iS prepared as in Ex~mple 22 using ~uccinyl chlori~e in place of malonyl chloride.

EXfample 2~
Preparation of N,N'-Bis~3-(N-2-hydroxyethy lf-20 ~aminocarbonyl)-5-(N-2,3-dihydroxypropyl-N-2:-: ~ hydroxyethylaminocarbonyl)-2,4,6-trliodophenyl3~oxamide.

~: The title compound is ~repared by reacting 3-N ~2 ~ acetoxyethyl~aminofarbonyl-5-aminio 2,4j6-triiodo~en~ioy~l ; chloride/ prepared~as in Example 18, $tep B, with QxalyI
:: 25 chloride in dioxane;~ reacting that profdUct with 3~ :2-: ~ hydroxyethy~f~mino-1,2-propanediol in DMAc; and : hydrolyzi~g th~ acetate groups with aqueous sulfurif ar~d gas in Example 18, Step E).
::
:

, WO g3t10825 P~r/uss2/l062s 212~i59 Example 28 PrPparation of N,N'-Bis~ N-2-hydroxyethyl-aminocarbonyl)-S-(N-2,3~dihydroxypropyl-N-2-hydroxyethylaminocarbonyl)-2,4,6-triiodophenyl]-S malondiamide.

The title compound is prepared as in Example 25 using malonyl chloride instead of oxalyl chloride.

Example_29 Preparation of N,N'-Bis[3-(N~2-hydroxyethyl-aminocarbonyl~-5-(N-2,3-dihydroxypropyl-N 2-hydroxyethytaminocarbonyl~ 2,4,6-triiodophenyl]-succinamide.

Th2 title co~pound is prepareld as in Example 25 using succinyl chloride in~tead of oxalyl chloride.

Example 30 ~:~ Preparation of N,N'-Bis[3-(N-~,3-dihydrox~propionamino-: carbonyt~-50(N-2,3 d:ihydroxypropyl-N-2-hydroxyethyl~
aminocarbonyl~-2,4,6-triiodophenyl3-malondiamide~

This compound is prepared by reacting two equivalents of : ~0 :5-amino-3-(N~-2,3-di~cetoxypropionaminocarbonyl~-2,4,6-triiodobenzoyl chloride with malonyl chloride, t~en : rea~ting the dimer with two eguivalents of 3-(N 2-: hydroxyethyl)amino-1,2-propanediol, and ~inally removinq the acetat~ groups by~hydrolysis.` ~ i ~:
Example -31 Preparation of N,N'-Bis[3-(N-2,3-dihydroxypropionamino-carbonyl~-5-(N-2,3-dihydroxypropyl--N 2-hydroxyethyl-aminocarbonyl)-2,4,6-triiodophenyl]-oxamide.

::

W(~9~/108~5 2 1 2 ~ ~ 5 9 PCT/US92/10629 The title compound is prepared as in Example 28 using oxalyl chloride instead of malonyl chloride.

Example 32 Preparation of N,N'-Blst3-(N-2,3-dihydroxypropionamino-carbonyl~-5-~N-2,3-dihydroXypropyl-N-2-hydroxyethyl-aminocarbonyl)-2,4,6-trilodophenyl~-succinamide~

The title compound is prepare~ as in Example 28 using succinyl chloride instead of malonyl chloride, Preparation of N,N'-dimethyl-~,N'-bis~3,5-bis~N-2~3-dihydroxypropyl-N-2-hydroxyethyl)aminocarbonyl]-2,4,6-trliodophenyl]-malondiamide.

The ~itle compound is prepared by reacting the product of Example 22 with~methyl iodide und~r basic, alkylating 15 ~conditlons.

: EXAMPLE 3~
~ ~ Preparation of~N,N/-:dimethyl-N,N~-bls~3,5-bis~N-2,3- :
:~ : dihydroxypropyl-N-2-hydroxyethyl)aminocarbonyl]-2~4,6-triiodophenyl]-oxamide.

:20~ Th~ ti~le ~ompound~is~prepared~by reacting the product of~
Example ~3 with methyl:iodide under~baslc, alXylati:nq~:
:conditions.

EXAMPLE_35 Preparation of N,N'-dimethyl-N,:N'-bis~3,5-bis(N-2,3-~: 25~ dihydroxypropyl-N-2-hydroxyethyl)aminocarbonyl~-2,4,6-: triiodophenyl~ ccinamide.

The ti~le compound is prepared by reacting the product of :~ : ~ : :

W093/iOX2s PcT/us92/lo62s 212'1~59 Example 24 with methyl iodide under basic, alkylati~g conditions .

Example 3~6 Preparation of NtN~-dimethyl-NrN/-Bisc3-(N-2-hydroxyethyl-amino~arbonyl)-5-(N~2,3~dihydroxyprvpyl-N-~-hydroxyethylaminocarbonyl)-2~4g6~triiodophenyl] oxamide.

The title compound is prepared by reacting the product of Example 25 with methyl iodide under basic, alkylating conditions.

10Example 37 Preparation of N,N'~dimethyl-N,~'-Bis[3-(N 2-hydroxyethyl-aminocarbonyl)-5-~N-2,3-dihydroxypropyl-N-2 hydroxye~hylaminocarbonyl)-2,4,6-triîodophenyl]-~alondiamide.
.
~he title compound i5 prepared by reacti:ng the product of Example 26 with methyl iodide under basic, alkyla~ing conditions.

ExamPle 38 Preparation of N,N' dimethyl-N,N'-~is~3-(N-2- ~
hydroxyethyl aminocarbonyl)-5-~N-2,3-dihydroxypropyl-N-2-~hydroxyethylaminocarbonyl~-2,4,6-triiodophenyl~-succinamide.
~ 1 : ' I ; ;
The title compound is prepa~ed by reacting the product of Example 27 with:methyl iodide under ~asic, alkyIating ~onditions.

:~ xample 3 Preparation of N/N'~dimethyl-N,N'~bis~3-~N-2,3 :
:

W(~'~3/t0825 2 l 2 ~ .;j 5 9 PC~/US92tlO629 dihydroxypropionamino~carbonyl)-5-(N-2~3 dihydroxypropyl~
N 2-hydroxyethyl-aminocarbonyl)-2/4,6-triiodophenyl]-malondiamide.

The title compound is prepared by reacting the product of Example 28 with methyl iodide under basic, alkylating conditions.

Example 40 Preparation of N,N'~dimethyl N,N'-bis[3-(N-2,3~
dihydroxypropionamino-carbonyl)-5-(N-2,3-dihydroxypropyl-N-2-hydroxyethyl-aminocarbonyl)-2,4,6-triiodophenyl~-oxamideO

The title compound is prepared by reacting the product of Example 29 with methyl iodide under basic, alkylating condîtions.

1~ ExamE~
Preparation of N,N'~dimethyl-N,N'-bis[3-(N-2,3-dihydroxypropionamino-car~onyl~-5-(N-2,3-dihydroxypropyl-N-2-hydr~xyethyl-ami~ooarbonyl)-2,4,6-triiodophenyl]-succinamide.
~ :
: 20 Th~ ti~le compound is prepared by rea~ting the product of Exampla 30 with methyl iodide under basic, alkylating conditions.

Exam~le_42 Preparation o~ 3-~N-2-hydroxyethyl)amino-1,2-propanediol ~Two methods~.

A. Glycidol (128 g, 115 ml, t.73 g-mol ) is added dropwise ove~ a l hour period to e~hanolamine (854 g, ~43 ml, 14.Q g-mole) with stirring, keeping the temperature WO ~3/10825 PCr/lJ~92/10629 2. ~ ~ 5 ~ 9 below 10 ~C. After the addltion is complete, the temperature is allowed to rise to room temperature and the solution is stirred for 20 hours. TLC analysis of the yellow solution indicates the reaction is complete.
The product is separated from the excess ethanolamine by Kugelrohr distillation (b.p. 170 - 182 C at 1 1.2 mm Hg) to give a colorless thick oil which solidifies on standing (196 g, ~4% yield~ 3C nmr spectrum and elemental analysis data are consistent ~ith the 10 struc:~ureO

B. 3-Chloro-1,2-propanediol (110.5 g, 1 g-mole) is added dropwise o~er a 3 hour period to ethanolamine ~305.4 ~, 5.0 g-mole) with stirring. The temperature of the~
reaction is kept at 10 - 15 C. After the addition i complete, the solution is allowed to warm to room temperature, th~n stirred overnight. The excess ethanolamine is removed by Ku~elrohr distill tion to yield 145 g oP a thick oil, the hydrochloride salt of the desired product. The oil is dissolved in 160 ml water.
To this solu~ion is added 50~ w~w NaOH solution (44.21 ml~ 33.8 g, 0.85 g-mole), with stirring, keeping the temperakure below 20 C. After the addition is complete, the solution is stirred overnight at room temperature.
, Water is removed by:rotary evaporation (80 C, under vacuum~ to yield an orange oil. The oil is dissolved in 1~5 ml of methanol to precipitate sodium chloride. The sal~ is fil~ered off and the filtrate is evaporated to yield 98.3 g o~ an orange oil7 The de~ired produc~ is~
isvlated fro~ this oil by Kugelrohr distillation (148 -: 30 168 C, 0.8-Q.9 mm Hg) to give a colorless oil which solidifies on standing (71 g, 53% yield). ~3C nmr data are consistent with the structure~

Claims

What is claimed is:

1. A compound of the formula:
wherein R1 is N(CH2CH2OH)CH2CHOHCH2OH; R2 equals NH2; R3 equals CH3, CH2OH, CH(CH3)OH, CHOHCH2OH, CH2OCH3, or CH2OCH2CH3; R4 equals H, CH3, CH2CH2OH, CH2CH2OCH3, CH2CHOHCH2OH, or CH2CHOHCH2OCH3; or R3 and R4 together form the group wherein n equals 0-3.

2. A compound of the formula wherein R1 is N(CH2CH2OH)CH2CHOHCH2OH; R2 equals NH2; R3 is H CH3, CH2CH2OH, CH2CHOHOH2OH, or CH2OCH3; and m equals 4.

3. The compound of Claim 1, wherein R4 is hydrogen.

4. The compound of Claim 1, wherein R4 is selected from the group consisting of CH3, CH2CH2OH, CH2CH2OCH3, CH2CHOHCH2OH, and CH2CHOHCH2OCH3.

5. The compound of Claim 1, wherein R3 and R4 together form the group

6. The compound of Claim 1, wherein R3 and R4 together form the group

7. The compound of Claim 2, wherein R2 equals NH2 and m equals 0.

8. The compound of Claim 2, wherein R2 equals NH2 and m equals 1.

9. The compound of Claim 2, wherein R2 equals NH2 and m equals 2.

10. The compound of Claim 2, wherein R2 is NH2.

11. A method for preparing a compound of the general formula wherein R2 is NH2, and R3 is selected from the group consisting of CH3, CH2OH, CH(CH3)OH, CHOHCH2OH, CH2OCH3, and CH2OCH2CH3, comprising the steps of a) reacting a compound selected from the group consisting of 5-amino-2,4,6-triiodo-3-(N-methylaminocarbonyl)benzoyl chloride, 3-[N-(2-acetoxyethyl)aminocabonyl]-5-amino-2,4,6-triiodobenzoyl chloride, and 5-amino-3-[N-(2,3-diacetoxypropyltaminocarbonyl]-2,4,6-triiodobenzoyl chloride; with a compound selected from the group consisting of acetyl chloride, methoxyacetyl chloride, ethoxyacetyl chloride, acetoxyacetyl chloride, 2-acetoxypropionyl chloride, and 2,3-diacetoxypropionyl chloride; under amide forming conditions, b. reacting the product of step a with 3-(N-2-hydroxyethyl)amino-1,2-propanediol under amide-producing conditions; and c. if acetate protecting groups are present, thereafter hydrolyzing the product of step b under hydrolyzing conditions to remove said acetate groups.

12. A method for preparing a compound of the general formula wherein R2 is NH2, R3 is selected from the group consisting of CH3, CH2OH, CH(CH3)OH, CHOHCH2OH, CH2OCH3, and CH2OCH2CH3, and R4 is selected from a group consisting of CH3, CH2CH2OH, CH2CH2OCH3, CH2CHOHCH2OH, and CH2CHOHCH2OCH3, comprising the steps of a) reacting a compound selected from the group consisting of 5-amino-2,4,6-triiodo-3-(N-methylaminocarbonyl)benzoyl chloride, 3-[N-(2-acetoxyethyl)aminocabonyl]-5-amino-2,4,6-triiodobenzoyl chloride, and 5-amino-3-[N-(2,3-diacetoxypropyltaminocarbonyl]-2,4,6-triiodobenzoyl chloride; with a compound selected from the group consisting of acetyl chloride, methoxyacetyl chloride, ethoxyacetyl chloride, acetoxyacetyl chloride, 2-acetoxypropionyl chloride, and 2,3-diacetoxypropionyl chloride; under amide forming conditions, b. reacting the product of step a with 3-(N-2-hydroxyethyl)amino-1,2-propanediol under amide-producing conditions; and c. reacting the product of step b with a compound selected from the group consisting of methyl halides, 2-haloethyl methyl ethers, haloethyl acetates, halo-2,3-propanediol, and 2,3-diacetoxyhalopropane under alkylating conditions; and d. if acetate protecting groups are present, thereafter hydrolyzing the product of step c under hydrolyzing conditions to remove said acetate groups.

13. A method or preparing a compound of the general formula wherein R2 is NH2 and n equals 0 to 1, comprising the steps of a) reacting a compound selected from the group consisting of 5-amino-2,4,6-triiodo-3-(N-methylaminocarbonyl)benzoyl chloride, 3-[N-(2-acetoxyethyl)aminocabonyl]-5-amino-2,4,6-triiodobenzoyl chloride, and 5-amino-3-[N-(2,3-diacetoxypropyltaminocarbonyl]-2,4,6-triiodobenzoyl chloride; with a compound selected from the group consisting of acetyl chloride, methoxyacetyl chloride, ethoxyacetyl chloride, acetoxyacetyl chloride, 2-acetoxy-propionyl chloride, and 2,3-diacetoxypropionyl chloride; under amide forming conditions, b. reacting the product of step a with 3-(N-2-hydroxyethyl)amino-1,2-propanediol under amide-producing conditions; and c. adding acetate protecting groups to the hydroxyl groups of the product of step a;
d. reacting the product of step b with a compound selected from the group consisting of 2,4-dibromobutyril bromide, 2-acetoxy-4-(methylthio)butyryl chloride, and 4-chlorobutyryl chloride under amide-producing conditions; and e. exposing the product of step c to cyclizing conditions such that butyrolactamide is formed;
f. hydrolyzing the product of step d under hydrolyzing conditions to remove the acetate groups.

14. A method or preparing a compound of the general formula wherein R1 is N(CH2CH2OH)CH2CHOHCH2OH, R2 is NH2, and m equals 0-2, comprising the steps of a) reacting 5-amino-2,4,6-triiodoisophthaloyl chloride with a compound selected from the group consisting of malonyl chloride, oxalyl chloride, and succinyl chloride under amide-forming conditions; and b, reacting the product of step a with 3-(N-2-hydroxyethyl)amino-1,2-propanediol under amide forming conditions.

15. A method for preparing a compound of the general formula wherein R1 is N(CH2CH2OH)CH2CHOHCH2OH, R2 is NH2, and m equals 0-2, comprising the steps of a. reacting a compound selected from the group consisting of 3-N-(2-acetoxyethyl)-amino-carbonyl -5-amino-2,4,6- triiodobenzoyl chloride, 5-amino-3-(N-2,3-diacetoxypropionamino-carbonyl)-2,4,6-triiodobenzoyl)chloride, and 5-amino-3-methylaminocarbonyl-2,4,6-triiodo-benzoyl chloride, with a compound selected from the group consisting of malonyl chloride, oxalyl chloride, and succinyl chloride under amide-forming conditions;
b. reacting the product of step a with 3-(N-2-hydroxyethyl)amino-1,2-propanediol under amide-forming conditions; and c. if acetate protecting groups are present, thereafter hydrolyzing the product of step c to remove said acetate groups.

16. A method for preparing a compound of the general formula wherein R1 is N(CH2CH2OH)CH2CHOHCH2OH, R2 is NH2 and R5 is selected from the group consisting of CH3, CH2CH2OH, CH2CHOHCH2OH, and CH2OCH3, and m equals 0-2, comprising the steps of a. reacting 5-amino-2,4,6-triiodoisophthaloyl chloride with a compound selected from the group consisting of malonyl chloride, oxalyl chloride, and succinyl chloride under amide-forming conditions;
b. reacting the product of step a with 3-(N-2-hydroxyethyl)amino-1,2-propanediol under amide-forming conditions;
c. reacting the product of step b with a compound selected from the group consisting of methyl halides, 2-haloethyl methyl ethers, 2-haloethyl acetates, halo-2,3-propanediol, and 2,3-diacetoxyhalopropane; and d. if acetate protecting groups are present, thereafter hydrolyzing the product of step c under hydrolyzing conditions to remove said acetate groups.

17. A method for preparing a compound of the general formula wherein R1 is N(CH2CH2OH)CH2CHOHCH2OH, R2 is NH2, R5 is selected from the group consisting of CH3, CH2CH2OH, CH2CHOHCH2OH, and CH2OCH3, and m equals 0-2, comprising the steps of a. reacting a compound selected from the group consisting of 3-N-(2-acetoxyethyl)-aminocarbonyl-5-amino-2,4,6-triiodobenzoyl chloride, 5-amino-3-(N-2,3-diacetoxypropion-aminocarbonyl)-2,4,6-triiodobenzoyl chloride, and 5-amino-3-methylaminocarbonyl-2,4,6-triiodobenzoyl chloride, with a compound selected from the group consisting of malonyl chloride, oxalyl chloride, and succinyl chloride under amide-forming conditions, b. reacting the product of step a with 3-(N-2-hydroxyethyl)amino-1,2-propanediol under amide-forming conditions;
c. reacting the product of step b with a compound selected from the group consisting of methyl halides, 2-haloethyl methyl ethers, 2-haloethyl acetates, halo-2,3-propanediol, and 2,3-diacetoxyhalopropane; and d. if acetate protecting groups are present, thereafter hydrolyzing the product of step c under hydrolyzing conditions to remove said acetate groups.

18. A radiological composition containing a compound of Claim 1 in a sufficient amount to provide satisfactory X-ray visualization together with a pharmaceutically acceptable radiological vehicle.

19. A radiological composition containing a compound of Claim 2 in a sufficient amount to provide satisfactory X-ray visualization together with a pharmaceutically acceptable radiological vehicle.

20. A method for X-ray visualization comprising injecting a radiological composition comprising a compound of Claim 1 in a pharmaceutically acceptable radiological vehicle in a sufficient amount to provide adequate visualization and thereafter carrying out X-ray visualization.

21. A method for X-ray visualization comprising injecting a radiological composition comprising a compound of Claim 2 in a pharmaceutically acceptable radiological vehicle in a sufficient amount to provide adequate visualization and thereafter carrying out X-ray visualization.

22. The compound [N-(2,3-dihydroxypropyl)-N-(2-hydroxyethyl)]-5-hydroxyacetylamino-2,4,6-triiodo-3-aminocarbonylbenzamide.

23. The compound [N-(2,3-dihydroxypropyl)-N-(2-hydroxyethyl)] -5-[(N-2-hydroxyethyl) hydroxyacetylamino] -2,4,6-triiodo -3-aminocarbonylbenzamide.

24. The compound [N-(2,3-dihydroxypropyl)-N-(2-hydroxyethyl)] -5-[(N-2,3-dihydroxypropyl) hydroxyacetylamino ] -2,4,6-triiodo -3 aminocarbonylbenzamide.

25. The compound [N-(2,3-dihydroxypropyl) -N- (2-hydroxyethyl)] -5-acetylamino-2,4,6-triiodo -3-aminocarbonylbenzamide.

26. The compound [N-(2,3-dihydroxypropyl) -N- (2-hydroxyethyl)] -5-[(N-2-hydroxyethyl)acetylamino]-2,4,6-triiodo -3-aminocarbonylbenzamide.

27. The compound [N-(2,3-dihydroxypropyl) -N- (2-hydroxyethyl)] -5-[(N-2-3-dihydroxypropyl)acetylamino]-2,4,6-triiodo -3-aminocarbonylbenzamide.