Patent GB-788975-A (GB)
Title: Improvements in or relating to photo-reproduction
IPC: C09B35/16
Filed: 1956-02-17
Abstract: Preparations of sulphonic or carboxylic acids of compounds containing two p-quinone-diazide sulphonic or carboxylic ester or amide groups or salts thereof are effected by:-  Alkaline condensation of benzidine-2,21-disulphonic acid with naphthoquinone-(1,4)-diazide-(4)-2-sulphonyl chloride.  Alkaline condensation of 4,41-diamino-stilbene 2,21-disulphonic acid with the same sulphonyl chloride.  Alkaline condensation of 2-amino-5-hydroxy-naphthalene-7-sulphonic acid with the same sulphonyl chloride.  Alkaline condensation of 1,3,5-resorcylic acid with the same sulphonyl chloride.  Alkaline condensation of N,N1 - bis - [5 - hydroxy - 7 - sulpho - naphthyl (2)] urea with 1 - chloro - 4 - nitrobenzene - 2 - sulphonyl chloride, treatment with sodium acetate and then sulphuric acid to convert the chloro group of the product to the hydroxy group, reduction of the nitro group with Raney nickel and diazotization to give the O(5),O1(51)-bis-ester of benzoquinone-(111,411) - diazide - (411) - 211 - sulphonic acid with the urea derivative.  Alkaline condensation of benzidine-2,21-disulphonic acid with 1-chloro-4-nitrobenzene-2-carboxylic acid to form the bis-carboxylic acid amide, conversion of the chloro to the hydroxy group, and reduction and diazotization of the nitro group to give the bis-amide of benzoquinone - (1,4) - diazide - (4) - 2 - carboxylic acid and the benzidine disulphonic acid.  Condensation of benzidine-2,21-disulphonic acid in the presence of pyridine with naphthaquinone - (1,4) - diazide - (4) - 2 - nitro - 7 - sulphonyl chloride, which is itself prepared by action of phosphorus pentachloride on the corresponding sulphonic acid.  Condensation of benzidine 2,21-disulphonic acid with 1-carbethoxy-hydroxy-4-nitro-naphthalene-6-sulphonyl chloride (itself prepared by hydrolysis of 4-nitro-1-acetamido-naphthalene-6-sulphonic acid to the corresponding 1-hydroxy compound and treatment of this with ethyl chlorocarbonate, followed by phosphorus pentachloride, reaction of the product with sodium dithionite to give 4,41-bis-(111-hydroxy-411 - aminonaphthalene - 611 - sulphonyl - amino) - diphenyl - 2,21 - disulphonic acid and diazotization thereof.  Condensation of 4,41-diaminostilbene with 1 - carbethoxy - hydroxy - 4 - nitro - naphthalene - 6 - sulphonyl chloride, reaction with sodium dithionite and diazotization similarly.  Reduction of the azo dye produced by coupling N,N1 - bis - (111 - naphthol - 211 carbonyl)-benzidine - 2,21 - disulphonic acid with benzene diazonium chloride (see Group IV (c)), with sodium dithionite, addition of hydrochloric acid to produce N, N1-bis-(111-hydroxy-411-amino-naphthalene -211-carbonyl)-benzidine-2,21-disulphonic acid and diazotization of this.  Alkaline condensation of benzidine 3,31-dicarboxylic acid with 1-carbethoxy-hydroxy-4-nitro-naphthalene-6-sulphonyl chloride, reduction of the product with sodium dithionite and then diazotization.ALSO:Benzidine 2,21-disulphonic acid is condensed with 1 - carbethoxy - hydroxy - 2 - naphthoic acid chloride to produce N,N1-bis-(1(11-naphthol - 211 - carbonyl) - benzidine 2,21 - disulphonic acid and this is coupled with two mol. of benzene diazonium chloride.  Tetrazotized benzidine 2,21-disulphonic acid is coupled with two mol. of 2,7-aminonaphthol and the resulting disazo dye is condensed with naphthoquinone-(1,4) - diazide - (4) - 2 - sulphonyl chloride.