US3257462A - Sulfoxide detergent compounds - Google Patents

Description

United States Patent a corporation of Ohio No Drawing. Filed Nov. 14, 1962, Ser. No. 237,715

5 Claims. (Cl. 260-607) This invention relates to novel 1,1-bis-sulfoxides and detergent compositions containing them.

In constant improvement of organic detergent compounds certain features have been found to be highly desirable. These features include resistance toward the ingredients imparting hardness to water and a high degree of detergency. Although there are a number of organic detergent compounds which have these characteristics, detergent compounds having additional desirable characteristics find a wider scope of application.

US. Patent 2,658,038, Wayne A. Proell, describes a class of 1,2-bis-sulfoxide detergent compounds which are relatively mild to the skin and which have elfective detergency characteristics. These 1,2-bis-sulfoxides have the formula.

where R is a lower alkyl, R is an alkyl containing 6 to 20 carbon atoms and R" is H or lower alkyl. Attempts to formulate these 1,2-bis-sulfoxide compounds into detergen compositions containing alkaline builder materials (for the purpose of enhancing the detergency of the 1,2- bis-sulfoxide detergent compounds) showed that the 1,2- bis-sulfoxides are subject to decomposition in the presence of such alkaline materials. Apparently, the presence of an alkaline material catalyzes the decomposition of a 1,2-bis-sulfoxide into odoriferous products (e.g., methyl disulfide), thereby reducing the effective amount of detergent and creating a severe odor problem. This decomposition problem indicated that bis-sulfoxides would generally be unsuitable for alkaline built detergent compositions.

It is an object of this invention to provide novel bissulfoxide detergent compounds having a high degree of detergency and stability in an alkaline environment. It is a further object of this invention to provide alkaline built detergent compositions containing such bis-sulfoxide compounds.

' It was found that these and other objects are achieved in a novel class of 1,1-bis-sulfoxides having the structure set-forth below and in alkaline detergent compositions containing such compounds, which'have a surprising alkaline stability, as hereinafter more fully described.

wherein R is an alkyl group containing from about 8 to about 16 carbon atoms, preferably in a straight chain, and R and R are alkyl groups containing from 1 to 2 carbon atoms. Preferably R and R are methyl.- The class of compounds described will hereinafter be referred to more simply as 1,1-bis-sulfoxides. Examples of the compounds of this invention are:

1,1-bis(methylsulfinyl) nonane 1,1-bis(methylsulfinyl) decane 1,1-bis(methylsulfinyl) undecane 1,1-bis(methylsulfinyl) dodecane 1,1-bis(methylsulfinyl) tetradecane 3,257,462 Patented June .21, 1966 ice 1,1-bis(methylsulfinyl) pentadecane 1,1-bis(methylsulfinyl) hexadecane 1,1-bis(methylsulfinyl) heptadecane 1,1-bis(ethylsulfinyl) tridecane l-(methylsulfinyl)-1-(ethylsulfinyl) tridecane, 1,1-bis- (methylsulfinyl) dodecane, 1,1-bis(methylsulfinyl) tridecane and 1,1-bis(methylsulfinyl) tetradecane are preferred compounds of this invention because of their 0ptimum detergency characteristics.

In general, the 1,1-bis-sulfoxides of this invention are prepared by synthetic methods involving the following steps:

' (1) Formation of 1,1-bis(alkylmercapto) alkane by reaction of a lower alkyl mercaptan with a higher alkyl aldehyde;

(2) Oxidation of the 1,1-bis(alkylmercapto) alkane, with H 0 for example, to form 1,1-bis(alkylsulfinyl) alkane (referred to herein as 1,1-bis-sulfoxides).

These steps are illustrated by the following exemplary equations where R is a C C alkyl group:

An alternative synthesis route can be followed:

1) The preparation of 1,1-bis(alkylmercapto) methane by reacting an alkali metal lower alkyl mercaptide with dihalomethane, e.g., dichloromethane;

(2) The alkylation of the 1,1-bis(alkylmercapto) methane, with a higher alkyl halide for example, in the presence of a strong base, such as sodamide, to form 1,1- bis(alkylmercapto) alkane;

(3.) Oxidation of the 1,1-bis(alkylmercapto) alkane, with H O for example, to form 1,1-bis(alkylsulfinyl) alkane (i.e., 1,1-bis-sulfoxide).

Thesesteps are illustrated by the following exemplary equations wherein R is a C C alkyl group:

CH Cl 2NaSCH CH (SCH +2NaCl In 1,1-bis-sulfoxides of this invention R in the above general formula can bederived from naturally occurring fats and oils or from synthetic sources. Mixtures of 1,1- bis-sulfoxides are very suitable wherein the R groups vary in chain length in the C to C range, as for example, the alkyl groups from coconut fatty alcohol or distilled coconut fatty alcohol.

The 1,1-bis-sulfoxides of this invention are useful per se as detergent and surface active compounds. The uses to which surface active compounds can be put are numerous and well known, e.g., preparing oil-in-water emulsions, textile treatment, dyeing, flotation, preparation of rubber'latex, and the like. Desirably the 1,1-bis-sulfoxides are used with alkaline builder materials to form built detergent compositions, as for example, liquid, bar, flake, granular or tabletted granular compositions. Such compositions have enhanced detergency characteristics due to the coaction in aqueous washing solution between the 1,1-bis-sulfoxides and the alkaline builder material. It is in such an alkaline medium that the surprising and ad vantageous usefulness of the 1,1'-bis-sulfoxides, i.e., superior stability in the presence of alkaline materials, is best demonstrated. Preferably the alkaline builder in such detergent compositions is a material selected from the class consisting of water soluble inorganic alkaline builder salts, water soluble organic alkaline sequestering builder salts and mixtures thereof. Desirably the ratio of 1,1- bis-sulfoxide to the alkaline builder material is in the range of about 4:1 to about 1:20. (Parts, ratios and percentages herein are by weight.) Preferably the alkaline vnesium sulfate.

milder material should provide a pH of about 8 to about [1 when the detergent composition is dissolved in water.

Water-soluble inorganic alkaline builder salts used alone or in admixtuie are alkali metal carbonates, boates, phosphates, polyphosphates, bicarbonates and silizates. (Ammonium or substituted ammonium builder salts, e.g., triethanolamine, can also be used.) Specific examples of such salts are sodium tripolyphosphate, soiium carbonate, potassium carbonate, sodium tetra- )orate, sodium pyrophosphate, potassium pyrophosphate, sodium bicarbonate, potassium triployphosphate, sodium hexametaphosphate, sodium sesquicarbonate, sodium monoand diortho phosphate and potassium bicarbonate. Such inorganic builder salts enhance the deiergency of the subject 1,1-bis-sulfoxides.

Examples of organic alkaline sequestrant builder salts used alone or in admixture to enhance detergency are alkali metal, ammonium or substituted ammonium, aminopolycarboxylates, e.g., sodium and potassium ethylenediaminetetraacetate, sodium and potassium N-(2- hydroxyet-hyl)-ethylenediaminetriacetates, sodium and potassium nitrilotriacetates and sodium, potassium and triethanolammonium, N-(Z-hydroxyethyl)-nitrilodiacetates. Mixed salts of these polycarboxylates are also suitable. The alkali metal salts of phyt-ic acid, e. g., sodium phytate are also suitable as organic alkaline-sequestrant builder salts (see U.S. Patent 2,739,942). Also suitable are the Water soluble salts of ethane-i-hydroxy-l,l-diphosphonate, e.g., the trisodium and tripotassium salts.

The detergent compositions of this invention can contain any of the usual adjuvants, diluents and additives, for example, anionic, nonionic, ampholytic, cationic or zwitterionic detergents, perfumes, anti-tarnishing agents, anti-redeposition agents, bacteriostatic agents, dyes, fluoresers, suds builders, suds depressors, and the like without detracting from the advantageous properties of the composition. Examples of anionic detergents are sodium-coconut soap, sodium dodecylbenzene sulfonate and potassium tallow alkyl sulfate. Examples of nonionic detergents are dodecyldimethylamine oxide and the condensation product of coconut fatty alcohol. with 5.5 moles of ethylene oxide. An example of zwitterionic detergent is 3-(N,N-dimethyl-Nhexadcylammonio)-2-hydroxypropane-l-sulfonate. An example of an ampholytic detergent is sodium-3-dodecylaminopropionate. An example of an alkaline-compatible cationic detergent is dodecylmethylbenzyl sulfoxonium methosulfate.

-Following are examples which illustrate the 1,1-bissulfoxide compounds and compositions of this invention. There are, of course, modifications of these illustrations which can be made by those skilled in the art without departing from the scope of this invention as defined in the appended claims.

EXAMPLE 1 Preparation of 1,1-bis(methylmercapto) dodeccme Lauraldehyde (113 g., 0.62 mole) was dissolved in 500 ml. of benzene and the solution cooled to C. The mixture was saturated with anhydrous hydrogen chloride at 0 and methyl mercaptan 108 g. (2.24 moles 80% excess) was bubbled in at 0 C. with stirring of the reaction mixture. Stirring was continued for 2 hours at 0 C. following completion of the addition of methyl mercaptan, and the mixture was allowed to stand overnight at 0 C. Separation of an aqueous layer occurred 'during the addition and subsequent standing. The mixture was washed with 50 ml. of water neutralized with :sodium bicarbonate solution followed by a water wash- .ing. The organic material was dissolved in ether, Washed twice with water, and the ether solution dried over mag- Following evaporation of the ether solwent the residual material was fractionally distilled to a 'yield 88.7 g. (55% yield) of 1,1-bis(methylmercapto) dodecane.

Preparation of 1,l-bis(methylsulfinyl) dodecane grams of 1,1-bis(methylmercapto) dodecane (0.305 mole) was dissolved in 200 ml. of ethanol, and 69 ml. of 30% hydrogen peroxide (0.67 mole, 10% excess) was added at room temperature with stirring. The mixture was warmed to 45 C. for 1 :hour until a monophasic system resulted. Following overnight standing of the reaction mixture, the solution was cooled to 10 C. and filtered. The filter cake was dissolved in refluxing acetone and recrystallized cooling to 10 C. The 1,1-bis(methylsulfinyl) dodecane obtained by filtration melted at 62.6- 65 C. and weighed 23.9 g. Further processing of the mother liquors at lower temperatures afforded recovery of additional 1,1-bis-sulfoxide. For example, an additional 5 g. of material substantially identical to the 23.9 g. crop obtained was obtained by additional chilling to 40 C. Infrared spectra of these crops show strong sulfoxide bands at 9.5 microns and no sulfone bands at the 7.6 and 8.8 micron positions. Further recrystallization affords concentrations of higher melting diastereoisomers (melting points up to C.) without any noticeable change in solution spectra. Analyses on the 1,1-bissulfoxide follow: Found: C, 58.3; H, 10.5; 0, 10.2. Calculated: C, 58.4; H, 11.1; 0, 10.4.

1,1-bis(ethy1sulfinyl) dodecane can be prepared in manner analogous to the process of Example 1 by using a molar equivalent amount of ethylmercaptan instead of methylmercaptan. 1,1 bis(methylsulfinyl)tetradecane can be prepared in a manner analogous to the process of Example -I by using a molar equivalent amount of myris taldehyde instead of lauraldehyde.

EXAMPLE II Preparation of 2,4-dithiapentane Methylmercaptan (96.2 g., 2.0 moles) was added to a solution of 80 g. (2.0 moles) of sodium hydroxide dissolved in 200 ml. of water and 300 ml. of ethanol While keeping the temperature at 0-10 C. Methylene chloride (84.9 g., 1.0 mole) was added to the resulting mercaptide solution at 10-15 C. The mixture was warmed to room temperature and an additional 25 g. of methylene chloride was added. The well-stirred mixture was heated to 60-70" for 1 hour. The lower layer was then separated and the upper aqueous layer extracted twice with petroleum ether. The petroleum ether extract was combined with the lower organic layer and washed twice with water and dried over magnesium sulfate. After evaporation of petroleum ether the yellow-orange organic residue was distilled through, a helices-packed column. Fractions boiling up to 146 C. were obtained and discarded. The product boiled at 146.5149, yield was 28.8 g. (27%). The product had a very strong mustard-cabbage odor.

Alkylation 0 2,4-dithiapentane To a solution of sodamide in 150 ml. of liquid ammonia, prepared in the conventional manner from 6.2 g. (0.27 g. atoms) of sodium metal catalyzed by 0.25 g. powdered ferric nitrate, was added 2,4-dithiapen-tane (28.8 g., 0.266 mole). The dithiapentane was added to the sodamide solution at the reflux temperature of ammonia and was stirred at the ammonia reflux temperature 1% hours. At the end of this period dodecyl bromide (66.2 g., 0.266 mole) was added dropwise to the stirred mixture. After addition was complete the ammonia was allowed to evaporate oif, and ethyl ether was added as necessary to maintain the mixture-liquid stirrable. After allowing the mixture to stand overnight, water was added and the organic layer separated. Following washing of the aqueous layer with ether and combining the ether extracts with the etheral solution, the

combined ether extracts were washed twice with an acidic ethanol-water solution. washed twice with water until neutral and dried over magnesium sulfate. After removal of the ether the product was fractionated through a Vigreaux column and the fraction boiling at l152l54 C. at 0.75 mm. of mercury was collected. The yield of the product, 1,1-bis(methylmercapto) tridecane, was 43.1 g. (58.5%). The product had refractive index n =1.4879, d =0.915. Sulfur analyses gave 22.93% sulfur (theory=23.18).

Oxidation of 1,1-bis(methylmercap-t) tridecane To 16.2 g. (0.059 mole) of 1,'1-bis(methy1mercapto) tridecane dissolved in 100 ml. of ethanol was added slowly, with stirring at room temperature, 6.0 g. (0.176 mole) of 30% aqueous hydrogen peroxide. The mixture was stirred until homogeneous and allowed to stand for 48 hours. The ethanol was evaporated in vacuo after the addition of platinum catalyst to enhance peroxide decomposition. After the removal of solvents the residue was dissolved in 400 ml. of hexane and filtered hot through a glass filter paper to remove catalyst. The filtrate was cooled slowly to room temperature, whereupon a crystalline fraction of the desired 1,1-bis-sulfoxide separated. This material was harvested by filtration. It melted at 8 8.5-'9 2 C. and weighed 4.6 g. Analyses gave percent C=5 8.29, percent H='.5 2; percent 0: 10.17 (theory: percent C=58.40; percent -H=11.10; percent 0: 10.37). Further' processing of the mother liquors can be carried out to yield more 1,1-bis-sulfoxide diastereoisomeric mixtures of lower melting point.

Built laundry detergent compositions containing 50% sodium tripolyphosphate, 30% sodium sulfate and 20% 1,1-bis(n1ethylsul'finyl) tridecane, resulting in lipid soil detergency properties (using naturally soiled cloth) superior to like formulations containing sodium dodecyl benzene sulfonate and approaching like formulations containing sodium tallow alkyl sulfate. The same basic formulation, but containing 1,1 bis'(methylsulfinyl) undccane of 1,1-bis(methylsulfinyl) pentadecane has satisfactory detergent char-acteristics but not as desirable as those compositions containing the C homolog. As regards detergency, these 1,1-bis-su1foxides in built compositions were about equal to 1,2-bis-sulfoxides in built compositions freshly prepared) containing, respectively, the same long chain alkyl groups.

As determined by guinea pig mildness tests, the 1,1- bis-sulfoxides of this invention, e.g., 1,1-bis(methylsulfinyl) tridecane, are very mild to the skin. Suoh guinea pig tests are described in Canadian Patent 639,398, issued April 3, 1962, to Howard F. Drew et al.

1,1-bis-sulfoxides, e. g., 1,1-bis(methylsul-finyl) tridecane, can be used per se as detergents for hand washing of woolens in aqueous solution of 1% concentration for example.

To test the alkaline stability of the 1,-1 bis-su1foxides, of this invention, particularly as compared to 1,2-bissulfoxides, 8% aqueous solutions of potassium pyrophos phate were used. A series of samples containing 3 grams of 1,1-bis(methylsulrinyl) tridecane in 150 ml. of the pyrophosphate solution was compared with a like series of 3 grams of 1,2-bis(methylsulfinyl) tetradecane in 150 ml. of the pyrophosphate solution. (The difierence in one methylene group was found to be not significant for purposes of the comparison.) The solutions were kept at 60 C. and pH 10. A slow stream of nitrogen was used to sweep volatile products into traps containing 3% aqueous mercuric chloride. Periodically the precipitated complex of the methyldisulride with mercuric chloride which formed in the traps was removed, dried and weighed to assess the rates of formation of decompositon products. :In 14 days the 1,1-bis-sulfoxide produced no precipitate. The 1,2-bis-sulfoxide produced 0.6 gram of precipitate in 1 day, 1.0 gram in 5 days and 1.1 grams in 12 days At this point, decomposition of The etheral extracts were then the 1,2-bis-sulfoxide was substantially complete This demonstrated the suprising alkaline stability of the 1,1- bis-sulfoxide as compared to the 1,2-bis-sulfoxide.

The 1,1-bis-sulfoxides of this invention can be used in efi'ective alkaline detergent compositions having the following formulations:

GRANULAR DETERGENT Percent 1,1-bis(methylsulfinyl) tride-cane 10 Sodium dodecylbenzene sulfonate (the dodecyl group being derived from tetrapropylene) 10 Sodium tripolyphosphate 50 Sodium sulfate 30 GRANULAR. DETERGENT Percent 1,l-bis(ethylsulfinyl) tridecane 10 Condensation product of one mole of dodecanol and twelve moles of the ethylene oxide 3 Sodium pyrophosphate 57 Sodium carbonate 3 Trisodium phosphate 3 Sodium sulfate 24 LIQUID DETERGENT Percent 1,1-bis(methylsulfinyl) undecane 6 Sodium dodecylbenzene sulfonate 6 Potassium pyrophosphate 10 Potassium nitrilotriacetate '10 Potassium toluene sulfonate 3 Sodium silicate 3.8- Carboxymethyl hydroxyethyl cellulose 0.3 Water, balance LIQUID DETERGENT Percent 1,1-bis(methylsulfinyl) pentadecane 5 Ethanol 10 Tetrasodium ethylenediaminetetraacetate .10

Water 75 What is claimed is: 1. 1,1-bis-sulfoxide detergent compounds having the formula:

References Cited by the Examiner UNITED STATES PATENTS 2,787,595 4/1957 Webb 252-138 2,870,216 1/ 1959 Sorensen et al. 260607 3,000,831 9/ 196 1 Tuvell 252-138 3,006,962 10/1961 Schultz et al. 260-607 3,006,963 10/1961 Buc et al. 260607 3.045,051 7/ 1962 Coma et a1. 260607 3,124,618 3/1964 Berry 260--607 OTHER REFERENCES Reid, Organic Chemistry of Bivalent Sulfur, vol. 2,

1960, page 26; and vol. 3, 1960, page 320.

CHARLES B. PARKER, Primary Examiner.

A. T. MEYERS, Examiner.

DELB-ERT R. PHILLIPS, Assistant Examiner.

Claims (1)

1. 1,1-BIS-SULFOXIDE DETERGENT COMPOUNDS HAVING THE FORMULA: