Patent GB-402265-A (GB)
Title: The manufacture of new hydroxythionaphthenes and indigoid dyestuffs derived therefrom
IPC: C09B7/00
Filed: 1933-01-11
Abstract: Dimethylalkoxybenzenethioglycollic acids having either a free ortho position or a group NH2, CN, CONH2 or COOH therein are obtained by customary methods from dimethylalkoxybenzenes which contain an amino group or a sulphonic group and a free ortho position thereto or both groups in ortho position to one another, and are then converted into the corresponding hydroxythionaphthenes in the usual manner. Dyestuffs are obtained by oxidising the latter, or by condensing them or their 2-anils with indigoid components.  Dyestuffs containing halogen may be obtained by starting with the halogenated dimethylalkoxybenzenes, by halogenating the intermediates e.g. the hydroxythionaphthenes or by halogenating the products.  In examples: (1) 2 : 3-dimethyl-4-hydroxybenzene-1-sulphonic acid, prepared by decomposing the diazo compound of 2 : 3-dimethyl-4-aminobenzene-1-sulphonic acid, is treated with dimethylsulphate and alkali and the resulting sodium salt of 2 : 3-dimethyl-4-methoxybenzene-1-sulphonic acid melted with phosphorus pentachloride; the 2 : 3-dimethyl-4-methoxyphenyl-1-thioglycollic acid obtained by reducing the resulting sulphochloride and condensing with chloracetic acid is converted first into the thioglycollic sulphochloride and then into the hydroxythionaphthene; by oxidising the 6 : 7-dimethyl-5-methoxyhydroxythionaphthene or by condensing with 2 : 1-naphthoxythiopheneanil dyestuffs are obtained; 4 : 5-dimethyl-7-methoxythionaphthene and the corresponding symmetrical dyestuff may similarly be obtained from 1 : 2 : 4-xylidine-5-sulphonic acid, and 3 : 4-dimethyl-6-methoxyphenyl-1-thioglycolic acid and 2 : 5-dimethyl-3-(and 4-)-methoxyphenyl-1-thioglycolic acid from the corresponding aminosulphonic acids: (2) 3 : 5-dimethyl-4-aminobenzene-1-sulphonic acid is transformed into 3 : 5-dimethyl-4-methoxyphenyl-1-thioglycollic acid as in example 1 and the 4 : 6-dimethyl-5-methoxyhydroxythionaphthene obtained by ring closure condensed with 5 : 7-dichlorisatin: (3) 4 : 6-dimethyl-7-methoxyhydroxythionaphthene is condensed with 4-methyl-5-chlor-7-methoxyisatinchloride: (4) 1 : 4-dimethyl-2-cyano-5-ethoxybenzene-3-thioglycollic acid is obtained from 1 : 4-dimethyl-2-amino-5 ethoxybenzene by treatment with sulphur chloride (c.f. Specification 17417/14, [Class 2 (iii), Dyes &c.]), saponifying, condensing with chloracetic acid and then treating with cuprous cyanide after diazotising the 1 : 4 dimethyl - 2 - amino - 5 - ethoxybenzene - 3 - thioglycollic acid; the 1 : 4-dimethyl-2-cyano-5-ethoxybenzene-3-thioglycollic acid is subjected to ring closure and hydrolysis and the resulting 4 : 7 - dimethyl - 6 - ethoxy - 3 hydroxythionaphthene condensed with 2 : 3-diketodihydrothionaphthene-2-p-dimethylaminoanil: (5) 1 : 2-dimethyl - 3 - methoxy - 6 - aminobenzene - 5 - sulphonic acid is converted to 1 : 2 - dimethyl-3-methoxy-6-cyanobenzene-5-sulphonic acid and the corresponding sulphochloride reduced, with simultaneous saponification to the 1 : 2-dimethyl-3-methoxybenzene-6-carboxyamide-5-mercaptan; by condensation with chloracetic acid and ring closure of the resulting thioglycollic acid, 4 : 5 - dimethyl - 6 - methoxy-3-hydroxythionaphthene 2-carboxylic acid is obtained, which is oxidised to the dyestuff or condensed with 6-methoxy-2 : 3-diketo-dihydrothionaphthene - 2 - p - dimethylaminoanil after removal of the 2-carboxylic group: (6) 1 : 3-dimethyl-4-hydroxy 5-nitrobenzene is methylated, reduced, acylated, chlorinated and saponified and the resulting 1 : 3-dimethyl-2-chlor-4-methoxy-5-aminobenzene diazotised, converted into the xanthogenate, saponified and condensed with chloracetic acid to obtain 1 : 3-dimethyl-2-chlor-4-methoxybenzene-5-thioglycollic acid; the latter is treated with chlorsulphonic acid or aluminium chloride, after conversion to the acid chloride, and the resulting 4 : 6-dimethyl-5-chlor - 7 - methoxy - 3 - hydroxythionaphthene oxidised to the symmetrical dyestuff, or condensed with 4 : 5-benzo-2 : 3-diketodihydrothionaphthene-2-p-dimethylaminoanil: (7) 1 : 4-dimethyl-2-chlorbenzene is nitrated, sulphonated and reduced and 1 : 4-dimethyl - 2 - chlor-3 - methoxybenzene - 5 - sulphonic acid obtained from the product by decomposing its diazo compound and methylating; by conversion to the acid chloride, reduction and condensation with chloracetic acid, 1 : 4-dimethyl-3-chlor-3-methoxybenzene-5-thioglycollic acid is obtained which is submitted to ring closure to produce the hydroxythionaphthene and oxidation to obtain the dyestuff; 4 : 7-dimethyl-5-chlor-6-ethoxy - 3 - hydroxythionaphthene is similarly produced from 1 : 4-dimethyl-2-chlor-3-ethoxybenzene-4-thioglycollic acid: (8) 1 : 4-dimethyl-5 - chlor - 6 - methoxy - 2 - cyanobenzene - 3 thioglycollic acid is prepared from 1 : 4-dimethyl-2-amino-6-methoxybenzene by the process used in example 4, and after conversion to 4 : 7-dimethyl - 5 - methoxy - 6 - chlor - 3 - hydroxythionaphthene is oxidised to the dyestuff or condensed with the 2-anils of 2 : 3-diketodihydrothionaphthenes or isatins, e.g., 4-methyl-6 - chlor - 2 : 3 - diketodihydrothionaphthene-2-anil, 6 - methoxy - 2 : 3 - diketodihydrothionaphthene-2-anil, 5 : 7-dichlorisatin-a -chloride or 4 - methyl - 6 - chlor - 7 - methoxyisatin - k - chloride; with 1 : 2-dimethyl-4-methoxy-6-aminobenzene as starting material, 4:5-dimethyl-6-chlor-7-methoxy-3-hydroxythionaphthene is obtained which may be oxidised or condensed with 4-methyl-6-chlor-2 : 3-diketodihydrothionaphthene-2-anil: (9) 1 : 4-dimethyl-2-methoxy-5-aminobenzene is acetylated, treated with bromine and saponified and the resulting base converted into the corresponding thioglycollic acid and hydroxythionaphthene by the customary methods; the 4 : 7-dimethyl-5-methoxy-6 brom-3-hydroxythionaphthene is condensed with 4-methyl-6-chlor-2 : 3-diketodihydrothionaphthene - 2 - p - dimethylaminoanil or with 4 : 6 - dimethyl - 5 : 7 - dichlorisatin - a  - chloride: (10) 1 : 2 - dimethyl - 3 - methoxy - 6 - aminobenzene is submitted to a similar series of reactions to those in the previous example but chlorine is used instead of bromine and the resulting 4-chlor-5-methoxy-6 : 7-dimethyl-3-hydroxythionaphthene is condensed with 4 - methyl - 6 - chlor - 2 : 3 - diketodihydrothionaphthene-2-p-dimethylaminoanil. Specification 215,021, [Class 2 (iii), Dyes &c.], also is referred to.