3-hydroxy-2-cyclobuten-1-one salts, their production and use
US5118847A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 9, 1991 |
| Grant date | Jun 2, 1992 |
| Priority date | — |
| Expiry date | Apr 9, 2011 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C2601/14
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.