Patent PL-159126-B1 (PL)
Title: Method for preparation of the new 4'-n,n-dimethylaminaze-2-nitrobenzene-4-sulfonic/dabs-no2cl/ acid chlorides
IPC: C09B29/08
Filed: 1989-04-08
Abstract: 1. Process of producing new chloride of 4'-N,N-Dimethylaminoazo-2-nitrobenzeno- 4-sulfonic /DABS-No2 Cl/, characterised in that sodium salt of 4-amino-3-nitrobenzenosulfonate acid is subject to diazotisation using the accepted methods, and the produced diazonium salt is combined with N,N-Dimethylaniline in acetic acid, the obtained dye is filtered and refined and subsequently crystallised from water by introducing sodium carbonate until carbon dioxide emission ceases, following cooling of the product it is filtered and rinsed in small volume of water and dried, next the product is ground with diethyl ether, filtered and rinsed with ether, subsequently it is chlorinated preferably with mixture of phosphorus pentachloride with methylene chloride or thionyl chloride or solution of formamide chloride in thionyl chloride, used in proportion 50-100% above the mass of the azo dye, the chlorinating process is conducted for 10-50 minutes in temperature of 40-60 degrees C preferably using ultrasounds, subsequently the product is  ground with sodium chloride until fine consistency is obtained, then the iced water is added to the mixture during the mixing process in proportion 0.5-1 dm<3> per 1/20-1/10 dye moles, the whole mixture is then stirred for approximately 15 minutes, filtered, rinsed in cold water and immediately dried in temperature of 40-60 degrees C, preferably with a blow drier and using drying agent and reduced pressure at the final drying stage, subsequently the dried product is subjected to continuous two phase extraction, initially with methylene chloride and then polar thinner, preferably acetone.2. Process of producing new chloride of 4'-N,N-Dimethylaminoazo-2-nitrobenzeno- 4-sulfonic /DABS-No2 Cl/, characterised in that the solution produced following the nitration of sulfonated acetanilide, using accepted methods, is introduced to mixture of water and ice in volume proportion 1:0.5-1:30, optimally 1:1, and the obtained mixture is being stirred until crystallisation process begins, the mixture is then cooled to approximately û15 degrees C and filtered, preferably under reduced pressure, and obtained deposit is rinsed with small quantity of cooled concentrated hydrochloric acid and then with diethyl ether and subsequently dried in 80-100 degrees C temperature, preferably with a blow drier, then obtained deposit is introduced to boiling water in volume proportion 1:1.4-1:5.0, optimally 1:1.6, then the solution separated from the deposit is cooled and mixed with concentrated hydrochloric acid in volume proportion 1:1, the crystallised product is separated and dried once it is cooled, alternatively solution separated from the deposit is saturated with gaseous hydrochloride in temperature close to 0 degree C, the deposit is then separated and dried, subsequently it is dissolved in water and combined with saturated Na2Co3 in such volume until emission of Co2 ceases, then the obtained sodium salt of 4-amino-3-nitrobenzenosulfonate acid is subject to diazotisation using the accepted methods, and the produced diazonium salt is combined with N,N-Dimethylaniline in acetic acid, the obtained dye is filtered and refined and subsequently crystallised from water by introducing sodium carbonate until carbon dioxide emission ceases, following cooling of the product it is filtered and rinsed in small volume of water and dried, next the product is ground with diethyl ether, filtered and rinsed with ether, subsequently it is chlorinated preferably with mixture of phosphorus pentachloride with methylene chloride oràààà.