Patent GB-257797-A (GB)
Title: Manufacture of new dyestuffs
IPC: C09B45/16
Filed: 1925-12-15
Abstract: 257,797. Imray, O. Y., (Soc. of Chemical Industry in Basle). Dec. 15, 1925. Monoazo dyes and chromium compounds thereof are made by coupling a barbituric acid of the general formula where R is hydrogen, or an aliphatic, aromatic, or aliphatic-aromatic residue, and n is 1 or 2, with an o-oxydiazo compound. The products are mordant dyestuffs and dye wool in an acid bath in red to brown tints; they yield chromium compounds which dye wool in tints varying from yellow to orange, brown, and red. In examples (1) 4-sulpho-2-aminophenol-6-carboxylic acid is diazotized and coupled with barbituric acid or with ethylbarbituric acid; the product dyes wool in yellow tints which become brownish when chromed, (2) 4-chlor-2-aminophenol-5-sulphonic acid is diazotized and coupled with benzylbarbituric acid, the product dyes wool yellowishbrown, becoming brick red when chromed, (3) 4- chlor-2-aminophenol-5-sulphonic acid is diazotized and coupled with phenylbarbituric acid, the product dyes wool in yellow tints, becoming orange when chromed, (4) 4-nitro-2-aminophenol is diazotized and coupled with diphenylene-4 : 41- dibarbituric acid; the product dyes wool in orange tints, becoming brown when chromed, (5) the dyestuff from diazotized 2-aminophenol-4-sulphonic acid and barbituric acid is converted into its chromium compound by treating with chromium formate solution, or with a solution made bv heating chromium hydroxide with caustic potash and glycerine, the product dyes wool in reddishyellow tints, (6) the dyestuff from diazotized 4- sulpho-2-aminophenol-6-carboxylic acid and barbituric acid is converted into its chromium compound by treating with chromium formate solution, and (7) the dyestuff from diazotized 4-chlor- 2-aminophenol-5-sulphonic acid and barbituric acid is converted into its chromium compound by heating with chromium fluoride solution. The properties of the dyestuffs and chromium derivatives made from the following components are tabulated : barbituric acid and 2-aminophenol-4- sulphonic acid, 6-nitro-2-aminophenol-4-sulphonic acid, 4-chlor-2-aminophenol-6-carboxylic acid, 4-nitro-2-aminophenol, 4-chlor-2-aminophenol, 2- aminophenol-4-sulphamide, 1-amino-2-oxynaphthalene-4-sulphonic acid, or nitrated 1-diazo-2- oxynaphthalene-4-sulpbonic acid; phenylbarbituric acid and 2-aminophenol-4-sulphonic acid, 4-chlor-2-aminophenol-6-sulphonic acid, 4-nitro- 2-aminophenol-6-sulphonic acid, 4-sulpho-2-aminophenol-6-carboxylic acid, 1-amino-2-oxynaphthalene-4-sulphonic acid or nitrated 1-diazo-2-oxynaphthalene-4-sulphonic acid; o-tolylbarbituric acid and 2-aminophsnol-4-sulphonic acid; p-tolylbarbituric acid and 4-chlor-2-aminophenol-5-sulphonic acid; p-chlorphenylbarbituric acid and 4- nitro-2-aminophenol-6-sulphonic acid; o-methoxyphenylbarbituric acid and 4-nitro-2-aminophenol- 6-sulphonic acid; p-nitrophenylbarbituric acid, and 4-chlor-2-aminophenol-5-sulphonic acid; alpha-naphthylbarbituric acid and 2-aminophenol.4- chlor-5-sulphonic acid; #-naphthylbarbituric acid and 4-nitro-2-aminophenol-6-sulphonic acid; and 4-oxy-3-carboxyphenylba.rbituric acid and 6-nitro- 2-aminophenol-4-sulphonic acid. Barbituric acids of the general formula set out above are prepared by condensing the corresponding ureas, of the formula R(NH-CO-NH2)n with a malonic acid ester. The ethyl, phenyl. o- and p-tolyl, benzyl, p-chlorphenyl, o-methoxyphenyl, m- and p-nitrophenyl, alpha- and #-naphthyl, o-carboxyphenyl, 4-oxy-3-carboxy-phenyl, and p-aminophenyl barbituric acids, and diphenylene-4 : 4<1>- and 3 : 31-ditolyl-4 : 4<1>-dibarbituric acids are tabulated with the ureas from which they are prepared. The diphenylene-4 : 4<1>-diurea, and 3 : 3<1>- ditolyl-4 : 4<1>-diurea, from which the two lastmentioned acids are obtained, are prepared from benzidine and tolidine respectively.