Preparation of 1,3-dibromo-2,2-dimethyl-propane-1,3-dicarboxylic acid derivatives

Abstract

In the preparation of a 1,3-dibromo-2,2-dimethyl-propane-1,3-dicarboxylic acid derivative of the formula ##STR1## in which R.sup.1 and R.sup.2 each independently is chlorine or alkoxy, by reacting a 2,2-dimethyl-propane-1,3-dicarboxylic acid derivative of the formula ##STR2## in which R.sup.3 is hydroxy or alkoxy and R.sup.4 is hydroxy, or R.sup.3 and R.sup.4 together are an anhydride oxygen atom, with an acid halide, then reacting the product with bromine at a temperature between 0.degree. and 150.degree. C. to form a 1,3-dibromo-2,2-dimethyl-propane-1,3-dicarboxylic acid chloride and optionally reacting such acid chloride with an alkanol, the improvement which comprises employing an acid chloride as the acid halide, e.g. phosphorus pentachloride, phosphorus oxychloride, phosphorus trichloride, thionyl chloride or phosgene. Compounds of the formula ##STR3## are new. The products are intermediates for making insecticides.

Dependencies are inferred from the claim text.