FR2619119A1 - cyanines - Google Patents

Abstract

Disclosed is a cyanine represented by the formula I: (CF DRAWING IN BOPI) wherein X is a group -NR2 R3 (wherein R2 and R3 are the same or different and each represents a hydrogen atom, a lower alkyl group or hydroxy lower alkyl) or lower alkoxy, Y is a hydrogen atom, a group -NR4 R5 (in which R4 and R5 are the same or different and each represents a hydrogen atom, a lower alkyl or hydroxy-lower alkyl group) , lower alkyl or lower alkoxy, R1 is an optionally substituted lower alkyl group and Z is an acidic residue, provided that in the case where Y is a hydrogen atom, X is not a lower alkoxy group.

Description

The present invention relates to new

cyanine compounds.

  Among inorganic recording media for semiconductor lasers, those containing a predominant amount of tellurium to form a recording layer are mainly used. However, tellurium type materials have the disadvantages

  to be toxic, to have low resistance to

  erosion, to be expensive and unsuitable for densification.

  We are currently trying to develop dyes

  organic materials that can replace inorganic materials

tellurium type.

  Important characteristics required for

  organic dyes useful as recording media

  are given below. These must exhibit: (1) remarkable absorption properties of light

  near infrared range of about 700 to 900 nm and

  to undergo fusion, sublimation, decomposition

  similar position and changes due to exposure to thermal energy

resultant; -

  (2) an advantageous ability to provoke

  sensing of light by the recording layer for the detection of signals in the reproduction; (3) good solubility in a solvent due to the need to form a recording layer by the wet coating method; (4) high stability of shape retention and excellent retention of recorded information and little risk of degradation due to irradiation of light during reproduction, resulting in

  the preservation of the information recorded

10 years or more.

  While organic dyes are advantageous

  in that their toxicity is low, their resistance to corrosion is high, they are inexpensive and

  lend themselves to densification compared to the inor-

  previous years, it was still necessary to develop a co-

  organic lorant which has the characteristic described above in Article (2) among the characteristics

required (i) to (4).

  An object of the present invention is to provide

  a cyanine compound useful as an organic dye capable of absorbing near-infrared light, which is useful as a recording medium on disk

  optical for a semiconductor laser.

  Another object of the invention is to provide a cyanine-type compound having the characteristics (1) to

  (4) which are required for organic coloring agents

  to absorb near-infrared, useful as media

  optical disc recording for a semiconductor laser

  driver. Another object of the invention is to provide a

  cyanine compound having such high reflectivity

  than that of inorganic materials of

  rium. Another object of the invention is to provide a cyanine compound having a remarkable solubility

in the solvent.

  Other aspects of the invention will be

  following the following description.

  The cyanine of the invention is a new compound

  which has not been described in the literature and which is

presented by formula (I):

2 6 19 1 1 9

CH3 CH3 CH3 CH3

X XCH = CH = C-) CH AT Z 7 _

I X -

Y R1 R Y

in which:

  X is a group -NR2R3 (o R e are identical to

  ticks or different and represent ch-c: r. an atom

  hydrogen, a lower alkyl or hydroxy group

  lower alkyl) or lower alkoxy, Y is an atom

  of hydrogen, a group -NR4R5 (o R4 and R5 are identi-

  different and each represent an atom of hy-

  a lower alkyl or lower hydroxyalkyl group), lower alkyl or lower alkoxy, R1 is an optionally substituted lower alkyl group and Z is an acid residue, provided that in the case where Y is a hydrogen atom, X is not an alkoxy group

inferior.

  Unexamined Japanese Patent Publication No. 85791/1984 discloses a compound (hereinafter referred to as "compound A") which is similar to the compound of the present invention and is represented by the formula:

CH3 CH3 CH3 CH3

CH3 OCC3

CH I CH = CH) - tCH AT C104

I I

CH3 CH3

  However, compound A, which has a mediocre

  in a solvent and composes a dye layer of low optical reflectivity, is not suitable as an infrared-absorbing organic dye procee, useful as a recording medium optically

by a semiconductor laser.

  Specific examples of representative groups

  X, Y, R1, R2, R3, R4, R5 and Z are indicated

below.

  Examples of lower alkyl groups are alkyl groups having 1 to 4 carbon atoms, such as

  the radicals methyl, ethyl, n-propyl, isopropyl, n-

  butyl, isobutyl, tert-butyl and the like.

  Examples of lower alkyl hydroxy groups are

  are alkyl groups having 1 to 4 carbon atoms and substituted with a hydroxyl group, such as hydroxymethyl, hydroxyethyl, 2-hydroxyethyl,

  3-hydroxypropyl, 4-hydroxybutyl, 2-hydroxy-2,2-dimethyl-

  ethyl, 2-hydroxy-1-methylethyl, 3-hydroxy-1-methylpro-

pyle and the like.

  Examples of lower alkoxy groups are the alkoxy groups having 1 to 4 carbon atoms, such as

  the radicals methoxy, ethoxy, n-propoxy, isopropoxy, n-

butoxy, tert-butoxy and the like.

  Examples of the group -NR2R3 and the group

  -NR4R5 are amino, N, N-dimethylamino, N, N-

  diethylamino, N-ethyl-N- (2-hydroxyethyl) amino, N, N-bis-

  (hydroxymethyl) amino, N, N-bis (hydroxyethyl) amino, N-

  methyl-N-ethylamino, N-methyl-N-n-propylamino, N-methyl-

N-n-butylamino and the like.

  Examples of lower alkyl groups,

  replaced by not only the groups

  coyles indicated above from 1 to 4 carbon atoms, but

  alkyl groups of 1 to 4 carbon atoms which can

  optionally carry at least one substituent selected from the group consisting of C 14 alkoxy, hydroxy, sulfo, carboxy, C 1-4 alkylamino, acetoxy

  and C 1 -C 4 alkoxycarbonyl, such as methoxymethyl, ethoxy-

  methyl, 2-methoxyethyl, 2-hydroxyethyl, 2-ethoxyethyl, 2- (n-butoxy) ethyl, n-butoxymethyl, - (CH2) n -SO3Na (or

  n is an integer from 1 to 4), - (CH2) n-COONa (where n is a

  tier 1 to 4), methylaminomethyl, dimethylaminomethyl,

  acetoxymethyl, methoxycarbonylmethyl and the like.

  Examples of group Z are a halogen atom

  gene, an alkyl sulphate residue, an aryl residue,

  sulfonate, a perchlorate residue, a tetra-

  fluoroborate, an arylcarboxylic acid residue and similar

  lar. When Z is a halogen atom, examples of Z are Cl-, Br, I-, F and the like. When Z is an alkyl sulphate residue, examples of Z

  are CH 3 SO 4, C 2 H 5 SO 4, n-C 3 H 7 SO 4, n-C 4 H 9 SO 4 and if

  milaires. When Z is an arylsulfonate residue,

  examples of Z are O-SO, CH3 SO3- and if-

  milaires. When Z is a perchlorate residue, examples of Z are C104 and the like. When Z is a tetrafluoroborate residue, examples of Z are BF and the like. When Z is an aryl carboxylic acid residue, examples of Z are COO 2.

and the like.

  The preferable compounds of the present invention

  are those in which X is an alkoxy group

  lower, Y is a lower alkoxy group, R1 is a lower

  lower alkyl or lower alkoxy lower alkyl

  and Z is a halogen atom or a perchlorate residue. Preferred compounds further include those wherein Y is substituted in the 6 or 7 position of the

  indolenine nucleus, particularly in the 6-position.

  The compound of formula (I) according to the present invention may be prepared by various methods, for example by

  example by the following method which can easily produce

  the compound and is therefore advantageous.

  The compound of the invention can be prepared by the reaction of an indolenium salt represented by the formula: CH 3 CHo

\ C

X

CH3.Z (2)

Y R1

  wherein X, Y, R1 and Z are as defined more

  and a conventional hydrochloride of f -anilino-acrylonitrile

  anion-anil represented by the formula: OS NH-CH = CH-CH = N-AECl (3) This condensation reaction is conducted

  in the presence of a fatty acid salt in an organic acid

  than anhydrous. Useful fatty acid salts are, for example,

  sodium acetate, potassium acetate, acetic acid,

  calcium tate, sodium propionate, potassium propionate similar. The fatty acid salt is used in an amount of about 0.5 to 3 moles, preferably

  from about 1 to 2 moles per mole of compound of formula (2).

  Examples of useful anhydrous organic acids are

  acetic anhydride, propionic anhydride, anhy-

  butyric dride, γ-butyrolactone and the like.

  The anhydrous organic acid is used in an amount of about 10 to 100 moles, preferably about 20 to

  moles per mole of the compound of formula (2). The proportions

  The compounds of formulas (2) and (3) are from about 0.2 to 1.5 moles, preferably from about 0.4 to 0.7 moles of the latter per mole of the former. The reaction is carried out regularly at a temperature of about 50 to 150 ° C, preferably about 100 to 140 ° C and is completed

about 10 to 60 minutes.

  The indolenium salts of formula (2) comprise

  new compounds that have not been described

  in the litterature. They can be prepared for example

  according to the following process (in which the compounds

  (2a) and (2b) are indolenium salts).

I I C H3 C H3

  Alkylating agent xC CH3 - tCH3'CB Ni / I

Y R1

(2 a)

CH3 CH3

Alkali x / H

2G N

Y R1

(7)

CH3 CH3

22> C113 Z2

Y R1

(2 b)

  o: Z1 is an acid residue other than a residue of

  chlorate and a tetrafluoroborate residue, Z2 is a perchlorate residue or tetrafluoroborate residue

  and X, Y and R 1 are as defined above.

  The reaction between the conventional aniline derivative of formula (4) and the standard 3bromo-3-methyl-2-butanone of (5) is carried out in the presence of an acid-binding agent. such useful agents are by

  pyridine, triethylamine, tri-n-propyl-

  amine, tri-n-butylamine and tertiary amines

  logues, sodium carbonate, potassium carbonate

  sium, calcium carbonate and alkali metal salts

  carbon acid analogs, sodium acetate, potassium acetate, calcium acetate and salts

  alkali metal analogues of acetic acids and the like

  lar. The acid-binding agent is used in a quantity

  about 0.3 to 5 moles, preferably about 0.5 to 1.5 moles per mole of compound of formula (4). The proportions of the compounds of formulas (4) and (5) are from about 0.3 moles to about 5 moles, preferably about

  0.5 to 1.5 moles of the last one per mole of the first. The reaction

  The reaction is carried out at a temperature in the range of from room temperature to about 2000C, preferably from about 50 to 150C and is completed in hours to about 25 hours, preferably about

at 3 pm

  The compound of formula (2a) can be prepared

  reaction of an alkylating agent with the indole derivative

  Lenin of formula (6). A useful alkylating agent is for example chosen from alkyl toluenesulphonates.

  such as methyl toluenesulfonate, toluenesulfonate

  ethyl nate, n-propyl toluenesulphonate,

  isopropyl luenesulphonate, n-toluenesulphonate

  butyl and the like, halogenated alkyls such as ethyl bromide, n-propyl bromide, n-butyl bromide, ethyl iodide, n-propyl iodide,

  n-propyl chloride, n-butyl chloride and the like

  salts, sulphates of dialcov

  dimethyl, diethyl sulfate and the like, a

  mixture of acid and epoxy compound (eg a mixture of hydrochloric acid, sulfuric acid or an acid

  inorganic analogue, acetic acid, propionic acid,

  and similar organic acid and ethylene oxide,

  propylene oxide or sitlaries), etc. The agent

  Coylant is used in an amount of about 0.3 to 5 moles, preferably about 0.5 to 2 moles per mole of the compound of formula (6). The reaction is carried out

  the absence or in the presence of a solvent. Solvents used

  include, for example, toluene, xylene and similar alkylbenzenes, n-octane, n-decane,

  cyclohexane, decalin and aliphatic hydrocarbons

  similar substances, benzene, naphthalene, tetralin

  aromatic hydrocarbons, trichloro

  ethane, tetrachloroethane, chlorobenzene, dichlo-

  robenzene and similar halogenated hydrocarbons, etc. The reaction is conducted at a temperature in the range of room temperature to about 200 ° C, preferably at about 50 ° C to 150 ° C and is completed in about 2 to 30 hours, preferably about 3 to

15 hours.

  The compound of formula (7) can be prepared by treating the compound (2a) with an alkali in a suitable solvent, such as water. The alkali to be used can be any conventional alkali as

  sodium hydroxide, potassium hydroxide and

  milaires. The amount of alkali used is about 1 to about moles, preferably about 1 to 5 moles per mole

  of compound (2a). The amount of solvent used is

  about 2 to 100 moles, preferably about 2 to 20 moles

  per mole of compound (2a). The reaction is carried out at a temperature of from 0 to about 150 ° C., preferably from about 0 ° C. to about 100 ° C., and is completed within a few dozen minutes to about 10 hours, preferably

in about 1 to 5 hours.

  The compound (2b) can be prepared by reacting the compound of formula (7) with the compound of formula (8) in the presence of a suitable solvent such as methanol.

  ethanol, n-propyl alcohol, isopropyl alcohol

  that n-butanol, isobutyl alcohol, alcoholic

  Butyl and similar alcohols, benzene,

  luene, xylene, n-octane, n-decane, cyclohexane,

  hexane, decalin, trichloroethane, tetrachloro-

  ethane, chlorobenzene, dichlorobenzene and

  similar hydrocarbons, etc. The proporticns of the

  Formulas (7) and (8) are from about 0.3 to about 11 moles, preferably from about 0.5 to about 3 moles of the latter.

  per mole of the first. The reaction is conducted at a time

  Oc temperature at around 70 ° C and is completed in

about 10 minutes to 3 hours. -

  The compound of the invention thus obtained can

  be easily separated and purified, for example by

  column matography, recrystallization and the like The compound of formula (I) according to the present invention

  The invention has high solubility in an organic solvent.

  like methanol, ethanol, diacetone alcohol

  or similar alcohols or dichloromethane, the di-

  chloroethane or similar aliphatic halogenated hydrocarbons. The compound implies a maximum of absorption

  between about 670 and 750 nm and has a high absorp-

  molar life. When used as a recording medium

  optical disk recording for semiconductor laser

  the compound of the invention has a high degree of

  flectivity for the reading laser light (780 nm) when

  of reproduction, its use is therefore interesting.

  An exemplary reference illustrating the preparation of a compound of formula (2) and preparation examples for obtaining compounds is provided below.

according to the present invention.

EXAMPLE OF REFERENCE

  A mixture of 15.36 g of 2,4-

  dimethoxyaniline, 16.06 g of 3-bromo-3-methyl-2-buta

  none and 8.0 g of pyridine at a temperature of 5

  550C for 5 hours. The reaction mixture was

  core treated at reflux for 7 hours. The acute reaction

  The reaction mixture was poured into 70 ml of water

  and the mixture was extracted with 30 ml of dichloromethane.

  The solvent was distilled off and the residue was distilled in vacuo to give 12.0 g of 2,3,3-trimethyl-5,7-dimethoxyindolenine having one dot.

  boiling point of 125 to 130 ° C / 2-3 m 2 Hg.

  A mixture of 10.96 g of 2,3,3-trimethyl-

  7-dimethoxyindolenine obtained above, 11.00 g of ethyl ptoluenesulphonate and 60 ml of toluene

  was refluxed for 8 hours. The reaction mixture

  was extracted with 50 ml of water,

  giving toluene sulfonate 1-ethyl-2,3,3-trimethyl-

  , 7-diméthoxyindolénium. The extract was added with 20 g of NaOH,

  at 20% and the mixture treated at 70 ° C. for 3 hours.

  The reaction mixture was extracted

  with 30 ml of toluene. Toluene has been hunted

  distillation and the residue subjected to vacuum distillation,

  yielding 6.00 g of 1-ethyl-2-methyl-3,3-dimethyl-5,7-

  dimethoxyindoline with a boiling point of 122 to

* 129 C / 3-4mmHg.

  2.87 g of 70% HC104 was added to a mixture

  4.95 g of 1-ethyl-2-methylene-3,3-dimethyl-5,7-dimethyl

  thoxyindoline and 60 ml of isopropanol at a temperature of

  The mixture was stirred at room temperature for one hour and cooled to a temperature below 5 C. The crystals deposited

  were separated by filtration, washed with

  propanol and dried, giving 6.54 g of 1-ethyl-2,3,3-trimethyl-5,7-dimethoxyindolenium perchlorate with a boiling point of 222.5 to 226.5 ° C.

PREPARATION EXAMPLE 1

  ml of acetic anhydride were added 4.75 g of the compound of formula (2) (in which X = N, N-dimethylamino, Y = hydrogen, R1 = methyl,

  Z = C104), 1.94 g of A-anilino-hydrochloride

  acrolein-anil and 2.5 g of potassium acetate.

  The mixture was refluxed for 10 minutes and poured into 350 ml of water. The deposited crystals were separated by filtration, washed with water and recrystallized

  from methanol, giving 3.44 g of the compound of

  mule (1) (wherein X = N, N-dimethylamino, Y = hy-

  R1 = methyl, Z = C104). The following is the melting point, the absorption maximum (t max) and

  the molar absorptivity (t) of the compound.

  Melting point: 219-221 C max: 732 nm (diacetone alcohol) t: 2.30 X 105 cm, 1

EXAMPLE 2 PREPARATION

  3.80 g of the compound of formula (1) (wherein X = N, N-dimethylamino, Y = hydrogen, R1 = ethyl, Z = ClO4) were produced by the procedure described in Preparation Example 1, with 4.96 g of compound of formula (2) (in which X = N, N-dimethylamino, Y =

  hydrogen, R1 = ethyl, Z = ClO4).

  Melting point: 195 - 200 ° C. max: 728 nm (methanol): 2.34 × 105 cm -1

PREPARATION EXAMPLE 3

  4.21 g of the compound of formula (1) (in which X = methoxy, Y = methoxy (position 7 of the indolenine ring

  the same below), R1 = ethyl, Z = C104) have been pro-

  prepared according to the procedure described in Preparative Example 1h with 5.22 g of the compound of formula (2) (wherein X = methoxy, Y = methoxy, (position 7), R1 =

ethyl, Z = C104).

  Melting point: 250 - 252 C% max: 693 nm (diacetone alcohol): 1.84 X 105 cm_1

EXAMPLE 4 PREPARATION

  The compound of formula (1) (wherein X = ethoxy, Y = ethoxy (position 7), R1 = ethyl, Z = CLO4) was produced according to the procedure described in Preparation Example 1 with the compound of formula ( 2) (in which X = ethoxy, Y = ethoxy (position 7), R1 = ethyl,

Z = C14).

  bmax: 698 nm (dichloromethane) t: 1.72 X 105 cm-1 Compounds were produced in Preparation Examples 22, repeating the procedure described

  in Preparation Example 1 with a suitable class

compound of formula (2).

EXAMPLE 5 PREPARATION

  Compound of formula (1) (X = N, N-dimethylamino,

  Y = methyl (position 7), R1 = methyl, Z = Co4).

  Amax: 737 (diacetone alcohol) ú: 2.20 X 105 cm1

PREPARATION EXAMPLE 6

  Compound of formula (1) (X = N, N-dimethylamino,

  Y = methoxy (position 7), R1 = ethyl, Z = Cl).

  Amax: 747 nm (diacetone alcohol) t: 2.28 X 105 cm -1

PREPARATION EXAMPLE 7

  Compound of formula (1) (X = N, N-dimethylamino, Y = hydrogen, R1 = ethyl, Z = C2H5SO4) bmax: 735 nm (diacetone alcohol): 2.10 X 105 cm-1

PREPARATION EXAMPLE 8

  Compound of formula (1) (X = N-ethyl-N- (2-hy-

  droxyethyl) amino, Y = hydrogen, R1 = ethyl.

  max: 735 nm (diacetone alcohol) -1: 2.10 X 10 cm1

PREPARATION EXAMPLE 9

  Compound of formula (1) (X = methoxy, Y = methyl

  thoxy (position 6), R1 = methoxymethyl, Amax: 702 nm (diacetone alcohol)%: 1.60 X 105 cm-1

EXAMPLE 10 PREPARATION

  Compound of formula (1) (X = methoxy, Y = methyl

  thyl (position 7), R1 = 2-hydroxyethyl, Z = C104).

  Amax: 679 nm (diacetone alcohol)%: 1.84 X 105 cm -1

EXAMPLE 11 PREPARATION

  Compound of formula (1) (X = methoxy, Y = methyl

  thyl (position 7), R1 = 2-methoxyethyl, Z = C104).

  / max (679 nm (diacetone alcohol): 1.85 X 105 cm -1

EXAMPLE 12 PREPARATION

  Compound of formula (1) (X = methoxy, Y = methyl

  thyl (position 6), R1 = n-propyl, Z = I).

  max 683 nm (diacetone alcohol)%: 1.74 X 105 cm-1

PREPARATION EXAMPLE 13

  Compound of formula (1) (X = ethoxy, Y = methyl

  thyl (position 7), R1 = ethyl, Z = BF4).

  Amax: 681 nm (dichloroethane) -1: 1.75 X 105 cm 1

PREPARATION EXAMPLE 14

  Compound of formula (1) (X = n-propoxy, Y = methyl (position 7), R1 = ethyl, Z = C104). Amax: 683 nm (diacetone alcohol)%: 1.63 X 105 cm -1

PREPARATION EXAMPLE 15

  Compound of formula (1) (X- = methoxy, Y = ethyl

  (position 7), R1 = ethyl, Z = C104).

  - $ max: 681 nm (diacetone alcohol): 1.82 X 105 cm-1

EXAMPLE 16 PREPARATION

  Compound of formula (1) (X = methoxy, Y = iso-

  propyl (position 7), R1 = methyl, Z = I).

  max: 681 nm (diacetone alcohol): 1.62 X 105 cm -1

EXAMPLE 17 PREPARATION

  Compound of formula (1) (X = methoxy, Y = methyl

  thoxy (position 6), R1 = n-butyl, Z = I).

  Smax: 703 nm (diacetone alcohol) i: 1.62 X 105 cm -1

PREPARATION EXAMPLE 18

  Compound of formula (1) (X = amino, Y = hydrogen

gene, R1 = ethyl, Z = C104).

max: 730 nm (diacetone alcohol)

t: 2.30 X 105 cm-

PREPARATION EXAMPLE 19

  Compound of formula (1) (X = N, N-bis (hydroxyl)

  methyl) amino, Y = hydrogen, R1 = ethyl, Z = C104).

  A max: 734 nm (diacetone alcohol): 2.13 X 105 cm1

EXAMPLE 20 OF PREPARATION

  Compound of formula (1) (X = methoxy, Y = methyl

  thoxy (position 6), R1 = n-butyl, Z = C104).

  max: 699 nm (dichloromethane) ú: 1.61 X 105 cm -1

PREPARATION EXAMPLE 21

  Compound of formula (1) (X = methoxy, Y = methyl)

  thoxy (position 7), R1 = acetoxyethyl, Z = ClO4). * max: 693 nm (diacetone alcohol): 1.75 X 105 cm-1

EXAMPLE 22 PREPARATION

  Compound of formula (1) (X = methoxy, Y = methyl

  thoxy (position 7), R1 = methoxyethyl, Z = I).

  > max: 695 nm (diacetone alcohol) t: 1.80 X 105 cm1

REFLECTION TEST

  Each of the cyanine dyes indicated

  in Table I below was dissolved in dichlo-

  romethane at a concentration of 20 g / l. The solution was applied to an acrylic plate by a coater rotating at 1500 rpm to form a layer of 600 to

  700 A thick, which was dried. Optimal reflection

  that was measured with a laser beam at 780 nm

  coming from the other side of the substrate. Table I below

after provides the results:

TABLE I

  Cyanine dye Optical reflectivity (%) Color of Ex. 1 of Prép. 40 Color of the Ex. '2 of Prep. 40 Color of the Ex. 3 of Prép. 42 Color of the Ex. 7 of Prép. 40 Color of the Ex. 20 of Prép. 41 Color of the Ex. 22 of Prép. 41 Compound A 24

SOLUBILITY TEST IN A SOLVENT

  Each of the cyanine dyes indicated

  below in Table II was dissolved in metha-

  nol and the solubility was determined at the temperature

  with the results provided in Table II.

TABLE II

  Cyanine dye Solubility (g / l) Color of Ex. 1 of Prép.

Colorant of Ex. 2 of Prép.

Colorant of Ex. 3 of Prép.

Colorant of Ex. 7 of Prép. > 30 Color of the Ex. 20 of Prép. > 30 Color of the Ex. 22 of Prép. > 30 Compound A up to 10

Claims (5)

  1. - Cyanine represented by the formula (I): ## STR2 ## CH 1 CH CH 2 CH + CH = CHY 2 CH (Z 1) Y R1 R1 Y   wherein: X is -NR2R3 (wherein R2 and R3 are the same or different and each represents a   hydrogen atom, a lower alkyl or hydroxy group   lower alkyl) or lower alkoxy, Y is a hydrogen atom, a group -NR4R5 (wherein R4 and R5 are the same or different and each represents an atom   hydrogen, a lower alkyl or hydroxy-al-   lower alkyl), a lower alkyl or alkoxy group   lower, R1 is an optionally lower alkyl group   is substituted and Z is an acid residue, provided that in the case where Y is a hydrogen atom, X is not a lower alkoxy group.   2. A compound according to claim 1, wherein   in that Z is a halogen atom or a residue of perchlorate.   3. The compound of claim 2, wherein   in that X and Y are both a group lower coxy.   4. A compound according to claim 3,   in that Y is substituted in position 6 or 7 of the indolenine nucleus.   5. A compound according to claim 4,   térisd in that R1 is a lower alkyl group or   lower alkoxy-lower alkyl.