US2957915A - N, n', alpha, alpha-tetrachloromalonamides - Google Patents

Description

N ,N,a,a-TETRACHLOROMALONAIVHDES Michael Kokorndz, Wyandotte, Mich., assignor to Wyandotte Chemicals Corporation, Wyandotte, Mich a corporation of 'Michigan No Drawing. Filed June 23, 1958, Ser. No. 744,013

4 Claims. (Cl. 260-561) This invention relates to new active chlorine bleach compounds. In a further aspect, this invention relates to new organic solid bleach compounds, one of which is, additionally, an outstandingly effective germicide.

Much effort has been expended in recent years towards the development of solid bleach compounds which are efficient bleaching agents while being safe under the conditions of use in the home and industry both with respect to the user and to the fabrics undergoing bleaching. Thus, a search is continuing for suitable solid bleach compounds which can replace the traditional hypochlorite solution bleaches, such as the solution bleaches based on sodium hypochlorite or calcium hypochlorite, which have been inconvenient to handle because they are available only in solution oiorm and which have been undesirable under use conditions because of the tendency to weaken fabric strength and to harm the hands of a person using the bleach. Some commercial acceptance has been found for such organic active chlorine bleach compounds as dichlorocyanuric acid, trichloroisocyanuric acid and 1,3- dichloro-S,S-dimethylhydantoin., Certain disadvantages have been found with all such known organic lactive chlorine solid bleach compounds and so the search continues for new and efiective organic solid bleach compounds.

An object of this invention, therefore, is to provide a new and effective active chlorine solid bleach compound.

A further object of this invention is to provide a method of bleaching cotton fabrics with a new active chlorine organic solid bleach compound.

A still further object is to provide a new method for preparing an organic solid bleach compound.

These objects and others have been accomplished in this invention by the discovery of new and effective active chlorine, organic solid bleach compounds corresponding to the formula wherein R is a methyl or ethyl radical. Thus, the new bleach compounds of this invention are N,N-dimethyl-N, N-u,a-tetrachlo-romalonamide and N,N'-diethyl-N,N-a,a tetrachloromalonamide. The new bleach compounds are readily prepared in high yields as white solids whichrequire little or no purification by the direct chlorination of the corresponding dialkylmalonamides. The new bleach compounds have been found tobe at least as effective in bleaching cotton fabrics as the known organic solid bleach compounds, and under some conditions, superior to such compounds, and surprisingly, N,N'-dimethyl- N,N-a,a-tetrachloromalonamide has been found to be a remarkably elfect-ive germicide, also.

The new bleach compounds of the invention can be formulated into desirable bleaching compositions by mixingin the substantially dry state'with alkaline salts, such as sodium carbonate, sodium borate, sodium silicate, tri- Patent P CC sodium phosphate, tetrasodium pyrophosphate, sodium triphosphate or mixtures of these. In addition, wetting agents, synthetic detergentsgenenally, soaps, fillers, abrasives and water softening agents of the inorganic or organic type may be incorporated in bleach compositions containing the new active chlorine organic bleach compounds vof the invention in order to impart special properties.

The new bleach compounds of the invention are characterized by a. high degree of stability when dry and may be stored for long periods of time and transported over considerable distances without substantial decomposition. When the new bleach compounds of the invention are dissolved in water, the ingredients of the mixture apparently react to yield hypochlorite chlorine which is responsible for the efiicient oxidizing, bleaching, disirfecting and sterilizing action.

The new bleach compounds of the invention are readily prepared as pure white solids in high yield and can be formed into tablets, sticks, cubes or agglomerates as well as in powdered form for use in bleaching operations.

The new bleach compounds of this invention are readily prepared by suspending N,N-dirnethylmalonamide or N,N-diethyhnalonamide in an aqueous alkaline solution, cooling the resulting mixture to below about 10 C. and passing chlorine gas into the cooled mixture until the pH of the mixture is about 7-5 while maintaining the temperature at no more than about 30 C.

The aqueous alkaline solution can be a solution of sodium or potassium hydroxide or any alkaline-reacting inorganic salt, such as sodium or potassium carbonate or bicarbonate. However, ammonium salts should not be used because of the danger of forming nitrogen trichloride. The amount of alkaline compound to be used must be 4 mol-equivalents per mol of dialkylnialonamide in order to obtain the theoretical yield of thetetrachlorosubstituted. product. Lesser amounts of alkaline compound will reduce the yield, and an excess is desirable.

The temperature of the mixture whilethe chlorine gas is passed in is desirably about 030 C. and preferably should not be substantially above about 10 C.

Chlorine gas is passed in over a period of time in the range of 2 to about 6 hours and. until the pHv of the reaction mixture is in the range of 7'5, desirably about 6.

When the addition of chlorine gas is completed the white solid product is easily separated from the reaction mixture byfiltration and air-dried.

The new active chlorine organic bleach compounds: of this invention and the method by which they can be prepared are illustrated in the following examples which are intended to illustrate theinvention without unduly restrictingit.

Example I N,N'-dimethylmalonamide was prepared by. the reaction of diethylmalonate with methylarnine as set forth in Beilstein, 4, 62; II, 565.

The new active chlorine bleach compound ofthe invention, N,N-dimethyl-N,N-a,a-tetrachloromalonamide was prepared by the chlorination of N,N-dimethylmalonamide. An alkaline solution in which the-chlorination was carried out was prepared by dissolving 221 grams (2.15 mols) of Na CO in 1550 ml. of water. The aqueous sodium-carbonate solution was cooled to 4 C. and grams (1 mol) of N,N'-dirnethylmalonamide were added' The pH after addition of the dialkylmalonarnide compound was 11.6.

Chlorine gas Was introduced to the aqueous alkaline solution of the dialkylmalonamide while cooling the mixture so that the temperature was in the range of 4-6 C. Chlorine gas was passed into the alkaline solution'over a period of about 5 hours until the pH was 6.0. The

white solid product which was produced was filtered and dried in air and weighed at room temperature.

A yield of 249 grams which was 92.5% of the theoretical amount of N,N'-dimethyl-N,N-a,a-tetrachloromalonamide was obtained. Analysis of the product showed the product to have a total chlorine content of 53.4% and an active chlorine content of 26.5%

The active chlorine bleach compound prepared was tested for bleaching activity by dissolving a suflicient quantity of the product in a liter of water so that the concentration of the product was suflicient to provide 200 parts per million of available chlorine. Half of this solution was cut fifty-fifty to provide a solution containing 100 parts per million available chlorine. Deionized water was used to prepare all solutions.

The bleaching tests were carried out six 4" x 4" swatches of unbleached muslin which were prepared for the tests by washing them five minutes in a Terg-O-Tometer at 75 cycles per minute at 140 F. in a 0.25 weight percent solution of a detergent composition consisting essentially of sodium alkylbenzenesulfonate, sodium carboxymethylcellulose and an inorganic alkaline salt such as is described in US. 2,566,501. The detergent composition employed had been prepared in one liter of demineralizecl Water. Thereafter, the swatches were rinsed under a demineralized water tap. After rinsing the washed swatches, the bleaching operation was carried out in the Terg-O-Tometer in the one liter of bleach solution prepared as described above for 15 minutes at 75 cycles per minute at 140 F.

After bleaching, the swatches were removed from the bleach liquor, rinsed under the demineralized water tap and pressed dry.

The bleaching eflectiveness obtained in each test was measured by standard light reflectance techniques. The light reflectance of the bleached swatches was compared to the light reflectance of the swatches before bleaching using a blue filter in a Hunter Multi-Purpose Reflectometer manufactured by Henry A. Gardner Laboratory, Inc., Washington, DC.

The test of the bleaching compound prepared in this example at 200 parts per million provided a 64.3% reflectance in the bleached swatch in one sample and a 65.7% reflectance in another carried out under identical conditions. The test of the compound at 100 parts per million provided a reflectance of 61.3%.

The new active chlorine bleach compound prepared in this example was also evaluated for germicidal activity using the Stuart-Ortenzio modification of the Cantor-Shelanski Increment Loading Method. In the test for germicidal activity, solutions of the new compound were prepared containing 50, 100 and 200 parts per million of available chlorine in sterile deionized water. Escherichia coli Was the test organism used in the work, and this was carried by daily transfer to fresh flasks of FDA Broth so that the work was done with the same culture of test organism. In the test used, 12 increments of loading consisting of 0.05 ml. each of an actively growing culture of the test organism were added to ml. of the test germicidal solution. The additions were spaced one and onehalf minutes apart. Exactly 60 seconds after the addition of an increment of loading, a standard 4 mm. loopful of the medication mixture was withdrawn from the medication tube and planted in a tube of sterile fluid thioglycollate medium, Difco. The subculture tubes were incubated two days at 35 C. and then read. All of the work was done with the medication tubes submerged in a thermostatically controlled water bath operating at 20 C., i0.5 C.

The test for germicidal activity with the compound of the invention prepared in this example showed that the test organism was killed within the exposure time of 60 seconds at all increments of loading of 1 through 12 increments with the solutions having 100 and 200 parts per million of available chlorine. The killing of the test or- 4 ganism at all increments of loading at 1 through 9 increments was found with the solution of the compound of the invention having 50 parts per million concentration of available chlorine.

The surprisingly effective nature of N,N'-dimethy1- N,N'-a,a-tetrachloromalonamide as a germicide and the unpredictability in this field are emphasized when one considers that N,N-diethyl-N,N-a,ot-tetrachloromalonamide, made and tested successfully as a bleaching compound in Example II was found to be completely ineffective in the same test for germicidal activity.

A second run for the preparation of N,N'-dimethyl- N,N'-u,a-tetrachloromalonamide was carried following the procedure described above. To a 20% aqueous solution of sodium carbonate (prepared by dissolving 122 grams of Na CO in 610 ml. of H 0) and cooled to 5 C., 65 grams (0.5 mol) of N,N-dimethylmalonamide was added. Chlorine gas was introduced into the mixture having a pH of 10.8 and continuously passed into the mixture for about 3 hours and 35 minutes at which time the pH of the reaction mixture was 6.0. The white solid product was filtered and dried in a desiccator. The yield was 119 grams of product having a melting point of 130132 C. which was of theoretical yield.

Analysis of the product showed it to contain 26.9% active chlorine and 55.5% total chlorine.

The product was tested for bleaching effectiveness according to the procedure described above and solutions of the product containing parts per million of available chlorine bleached the swatches to the extent of 65.4% reflectance at pH 4, 67.8% reflectance at pH 7 and 63.5% reflectance at pH 10. These results are generally equal to or superior to the bleaching eifectiveness of 1,3-dichloro 5,5 dimethylhydantoin which gives bleached swatches under comparable conditions having 66.2-67.2% reflectance at pH 4, 64.2-65.9% reflectance at pH 7 and 61.5% reflectance at pH 10.

Example II N,N-diethylmalonamide was prepared by the reaction of diethylrnalonate with ethylamine by the method cited at the beginning of Example I.

The N,N' diethyl N,N-a,a-tetrachloromalonamide compound of the invention was prepared by suspending 158 grams (1 mol) of N,N-diethylmalonamide in a solution of 222 grams (2.1 mols) of Na CO in 1550 m1. of water which was cooled to 4 C. The pH of the alkaline solution of the dialkylmalonamide was 11.0.

Chlorine gas was introduced to the aqueous alkaline solution of the dialkylmalonamide while maintaining the temperature of the reaction mixture at 6 C. to 4 C. over a period of about 3 hours and until the pH was 6.0

The white solid product which resulted was filtered and dried in air for 24 hours.

A yield of 234 grams which corresponded to 80% of the theoretical amount of product was obtained which had a melting point of 85-87 C., an active chlorine content of 23.8% and a total chlorine content of 45.7%.

A test for bleaching activity of this compound of the invention was carried out according to the method set forth in Example I above employing a solution of the compound of the invention providing 200 parts per million of chlorine at F. and the percent reflectance of the bleached cotton swatch was 64.3.

It should be apparent that the new active chlorine organic solid bleach compounds of this invention are effective for bleaching cotton fabric and that N,N-dimethyl-N,N'-a,a-tetrachloromalonamide is a surprisingly effective germicidal agent, also. The new compounds are, therefore, the basis for new methods and compositions for bleaching cotton fabrics employing these compounds as the active agent. Also, the new method by which organic solid bleach compounds have been prepared is considered as an embodiment of this invention.

wherein R is a member selected from the group consisting of methyl and ethyl radicals.

2. Compound corresponding to the formula if t e CHa-NCC-GNCHE 3. Compound corresponding to the formula 4. A method for making an active chlorine bleach compound, which comprises, suspending an N,N-dialkylmalonamide selected from the group consisting of N,N'- dimethylmalonamide and N,N'-diethylmalonamide in an aqueous alkaline solution containing at least 4 mol equivalents of alkaline compound per mol of N,N- dialkylmalonamide, cooling the resulting mixture to a temperature in the range of about 0-30 C., and passing chlorine gas into the cooled mixture until the pH of the mixture is about 7-5 while maintaining the temperature at no more than about 30 C.

References Cited in the file of this patent UNITED STATES PATENTS 2,152,532 Carlisle Mar. 28, 1939 2,383,900 Vincent et al. Aug. 28, 1945 2,856,427 Bruce et al. Oct. 14, 1958 2,864,861 Wohnsiedler et al. Dec. 16, 1958

Claims (1)

1. COMPOUNDS CORRESPONDING TO THE FORMULA