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.
一般公式为:##STR1## 的3-羟基-2-
环丁烯-1-酮盐,其中R是一般公式为:##STR2## 的
铵基,其中R.sub.1,R.sub.2和R.sub.3在含义上相同或不同,每个都是氢原子,低级烷基或环烷基,或R是碱
金属原子。公式I的盐可通过纯3-乙酰氧基-2-
环丁烯-1-酮,或1,3-环
丁二酮或含有3-乙酰氧基-2-
环丁烯-1-酮的二羰基产物的蒸馏残渣与碱反应而得到。碱可以是一般公式为:##STR3## 的胺,其中R.sub.1,R.sub.2和R.sub.3具有上述含义,或碱
金属醇盐或碱
金属氢氧化物。公式I的盐适用于生产
方酸,其在第一步中被卤代,然后在第二步中被
水解为
方酸。