3-hydroxy-2-cyclobuten-1-one salts, their production and use

Abstract

3-Hydroxy-2-cyclobuten-1-one salts of the general formula: ##STR1## wherein R is an ammonium group of the general formula: ##STR2## wherein R.sub.1, R.sub.2 and R.sub.3 are the same or different in meaning and each is a hydrogen atom, a lower alkyl group or a cycloalkyl group or R is an alkali metal atom. The salts according for formula I are obtained by the reaction of pure 3-acetoxy-2-cyclobuten-1-one, or 1,3-cyclobutanedione or a distillation residue of the diketene production containing 3-acetoxy-2-cyclobuten-1-one, with a base. The base can be an amine of the general formula: ##STR3## wherein R.sub.1, R.sub.2, and R.sub.3 have the above-mentioned meaning, or an alkali metal alcoholate or an alkali metal hydroxide. The salts according to formula I are suitable for the production of squaric acid, by their being halogenated in a first step and then being hydrolyzed to squaric acid in a second step.

Dependencies are inferred from the claim text.