GB390556A - The manufacture of nitro compounds of the diphenyl series - Google Patents

Abstract

Nitro compounds of the diphenyl series are made by nitrating diphenyl derivatives negatively substituted in 4-position with a quantity of nitric acid not substantially exceeding the theoretical amount for the introduction of one nitro group into the molecule in the presence of sulphuric acid, a simultaneous sulphonation being practically avoided by working at relatively low temperatures or by decreasing the sulphonating effect of the sulphuric acid by adding a diluent, e.g. glacial acetic acid or water. In examples, (1) 4<1>-nitrodiphenyl-4-carboxylic acid mixed with the 2<1>-nitroderivative is made by treating diphenyl-4-carboxylic acid with nitric and sulphuric acids with or without acetic acid; 4<1>-amino-, 4<1>-hydroxy-, 4<1>-chloro- and 4<1>-bromo-diphenyl-4-carboxylic acids and 4<1>-nitro-diphenyl-4-carboxylic acid chloride are prepared from the 4<1>-nitro compound by the usual methods; the crude nitration product may be directly reduced and the amino compounds separated by means of the sodium salts, (2) 4-benzoyldiphenyl (from benzoyl chloride and diphenyl by Friedel-Craft's reaction) is nitrated as in (1) to yield-4<1>-nitro-4-benzoyldiphenyl which may be reduced to the 4<1>-amino compound; 4<1>-nitro- and 4<1>-amino-4-acetodiphenyl are similarly obtained from 4-acetodiphenyl, (3) diphenyl-4-sulphonic acid is nitrated as above to form a mono-nitro derivative which yields the corresponding amino compound on reduction, (4) 4-nitrodiphenyl similarly yields 4 : 4<1>-dinitrodiphenyl.