GB644051A - Improvements in process of manufacture of 2, 2-bis-(4-methoxyphenyl) 1, 1, 1-trichloroethane - Google Patents

Abstract

2 : 2-Bis-(4-methoxyphenyl)-1 : 1 : 1-trichloroethane is prepared by treating anisole and chloral with about 95 to 98 per cent sulphuric acid in the proportions of at least three moles., e.g. 3-5 moles., each of anisole and sulphuric acid for each mole. of chloral to form a liquid reacting system whilst agitating and cooling to below 20 DEG C. and separating the organic phase containing the product from the acid phase containing water and sulphonated anisole. In a preferred process, the anisole and chloral are mixed at below 20 DEG C. and the acid added as rapidly as possible, with cooling to maintain the mixture at 20 DEG C. The acid recovered may be used again after fortification with stronger acid. The two phases obtained after reaction may be separated, preferably below 20 DEG C., or a centrifuge may be employed. The organic phase is washed with water or dilute ammonia, anisole removed by steam distillation, and the product cast into blocks or granulated. It may then be pulverized or recrystallized. Alternatively, the whole reaction mixture may be poured into water. The Specification as open to inspection under Sect. 91 comprises also reaction temperature which is not restricted to 20 DEG C. or less, and no limitations are imposed on the reactants with regard to the proportions in which they may be used. This subject-matter does not appear in the Specification as accepted.