Patent GB-426403-A (GB)
Title: Process for the manufacture of hydroxydiphenylene compounds and derivatives thereof
IPC: F16C33/78
Filed: 1933-10-03
Abstract: Hydroxydiphenylene compounds of the general formula <FORM:0426403/IV/1> in which X represents O, S, SO or SO2, are obtained by boiling the diazo compounds of the corresponding primary amines in aqueous solution in presence of phosphoric acid and, if desired, in presence of copper or a copper compound as catalyst.  The following examples are specified.  (1) 2-Aminodiphenylene-oxide in dilute sulphuric acid is diazotized by dropping in at 50--60 DEG  C. a concentrated sodium nitrite solution, the solution is filtered, concentrated sulphuric acid is added to the filtrate, the diazonium sulphate, which crystallizes out on cooling, is filtered off and, without drying, mixed with technical phosphoric acid and p  dropped into a flask heated to 200 DEG  C. supplied with superheated steam; the 2-hydroxydiphenylene-oxide which distils off is purified by dissolving in caustic soda solution and precipitating with hydrochloric acid.  (2) 2 - Aminodiphenylene - oxide is dissolved in technical phosphoric acid by heating at 100--110 DEG  C. and the solution is cooled to 0--5 DEG  C., at which most of the 2 - aminodiphenylene-oxide phosphate crystallizes, and diazotized by addition of dilute sodium nitrite solution; the diazo solution, filtered if necessary, is dropped into a flask, heated to 200--210 DEG  C. containing technical phosphoric acid into which superheated steam is passed; 2-hydroxydiphenylene-oxide separates from the distillate.  (3)-Aminodiphenylene-oxide is converted by the method of (2) into 3-hydroxydiphenylene-oxide.  (4) 2 - Aminodiphenylene - sulphide, dissolved in technical phosphoric acid, is cooled to 0--5 DEG  C. and diazotized by addition of dilute sodium nitrite solution; the diazo solution is dropped into a flask, heated to 180--200 DEG C. by the passage therethrough of superheated steam; 2-hydroxydiphenylene-sulphide separates from the distillate.  (5) 2-Aminodiphenylene-sulphoxide and 3-aminodiphenylene-sulphone are converted by the method of (4) into 2-hydroxydiphenylene-sulphoxide and 3-hydroxydiphenylene-sulphone respectively.  o-Carboxylic acids of the above hydroxydiphenylene compounds are obtained by treating them, in the form of their alkali metal salts or with the addition of an alkali, with carbon dioxide at elevated temperature and pressure. The following examples are specified. (6) The potassium salt of 3-hydroxydiphenylene-oxide is ground with potassium carbonate and the mixture is heated for 8--10 hours in an autoclave at 210--220 DEG  C. to which carbon dioxide is supplied under pressure; the reaction mixture is dissolved in hot water, filtered, and the potassium salt of 3-hydroxydiphenylene-oxide-2-carboxylic acid is crystallized out from the filtrate; this is dissolved in hot water and acidified with hydrochloric acid to precipitate the free acid; 2-hydroxydiphenylene-oxide is similarly convertible into the corresponding 3-carboxylic acid.  (7) The sodium salt of 3-hydroxydiphenylene-sulphide is treated with carbon dioxide as in (6) to obtain the corresponding 2-carboxylic acid.  (8) The potassium salts of 3 - hydroxydiphenylene - sulphone and 3-hydroxydiphenylene - sulphoxide are treated with carbon dioxide as in (6) to obtain the corresponding 2-carboxylic acids.  Arylamides of o-hydroxycarboxylic acids of diphenylene compounds are obtained from the acids by methods known per se, e.g. (a) by reaction of the amine with the chloride or an ester of the acid, (b) by heating a solution of the amine and the acid in an inert organic solvent with addition of phosphorous oxychloride or trichloride, (c) by reaction of the acid with the isocyanic ester corresponding to the amine (cf. Specification 289,037, [Class 2 (iii)]).  The following examples are specified. (9) 3-Hydroxydiphenylene - oxide - 2 - carboxylic acid and 1 - amino - 2 - methoxy - 4 - chlorobenzene are dissolved in toluene at 60--65 DEG  C., phosphorus trichloride is dropped in while stirring and the solution is boiled for 8 hours; the toluene and excess amine are removed by steam, the solution is made alkaline with sodium carbonate and the residue is filtered off, washed with water, dissolved in dilute caustic soda and treated with hydrochloric acid to precipitate the free arylamide; the acid may be replaced by 2 - hydroxyphenylene - oxide - 3 - carboxylic acid. (10) The arylamide from 3-hydroxydiphenylene-sulphide - 2 - carboxylic acid and 1 - amino - 2 - methoxy-4-chlorobenzene is similarly prepared; the acid may be replaced by 3 - hydroxydiphenylene-sulphone-2-carboxylic acid. 3-Aminodiphenylene-oxide is obtained by heating 3-bromodiphenylene oxide with concentrated aqueous ammonia for 10 hours at 200--220 DEG C. in presence of a copper salt.  2-Aminodiphenylene-sulphoxide is obtained by reducing the nitro group of the product of nitration of diphenylene sulphoxide.  3-Aminodiphenylene-sulphone is obtained by reducing the nitro group of the product of oxidation of 3-nitrodiphenylene sulphide with hydrogen peroxide in glacial acetic acid.  The Specification as open to inspection under Sect. 91 comprises also additional subject-matter as follows: (a) an alternative to the process of example (2) in which the diazo solution is dropped into a boiling solution of phosphoric acid, until a test portion no longer couples with a component, the solution being then diluted and the product filtered off or extracted with a solvent; (b) an alternative to the process of example (6) in which a mixture of 3-hydroxydiphenylene-oxide and potassium carbonate is heated for 5--6 hours at 150 DEG  C. in an autoclave to which carbon dioxide is supplied under pressure; (c) replacement of the amine in example (9) by aniline, 2-toluidine, 2- or 4-anisidine, 2-phenetidine, 2- or 4-chloraniline, 3-nitraniline, 1-amino-2 : 5- or 3 : 5-dimethylbenzene, 1-amino-2- or 3-methyl-4-methoxy benzene, 1 - amino - 2 - methyl - 4 - or 5-chlorobenzene, 1-amino-2 : 4- or 2 : 5-dimethoxybenzene, 1-amino-2-methoxy-5-chlorobenzene, 1 - amino - 2 - sulphondiethylamido - 4 - chlorobenzene, 1-amino-2 : 4 : 5- or 2 : 5 : 4-dimethoxychlorobenzene or 1-naphthylamine; (d) replacement of the amine in example (10) by a number of those specified in (c) or by 4-phenetidine, 2 - nitraniline, 1 - amino - 3 : 4-dichlorobenzene, 2 - amino - 6 - ethoxybenzothiazole or 1 - amino - carbazole; (e) the preparation by the process of example (9) of the arylamide from 3-hydroxydiphenylene - sulphide - 2 - carboxylic acid and dianisidine.  This subject - matter does not appear in the Specification as accepted.