Treatment of waste water from the preparation of 6-substituted 3-mercapto-4-amino-1,2,4-triazine-5-ones
US4058526A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 11, 1976 |
| Grant date | Nov 15, 1977 |
| Priority date | — |
| Expiry date | May 11, 1996 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07D253/075
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A process for the treatment of waste water obtained in the condensation of thiocarbohydrazide and an aqueous solution of an .alpha.-keto carboxylic acid such as, e.g., 3,3-dimethyl-2-oxo-butyric acid, which comprises mixing said waste water with a water-immiscible ketone, preferably selected from the group consisting of methyl isobutyl ketone, cyclohexanone and pinacolone, said ketone being employed in an amount sufficient to form two phases, separating said two phases, and discharging as waste the aqueous phase. Advantageously the pH of the waste water is no higher than about 6 and its temperature is 20.degree. to 50.degree. C. The organic phase comprises the ketone containing dissolved therein an adduct of the ketone with thiocarbohydrazide and/or similar amino materials originally present in waste water. The excess of the ketone may be recovered from the organic phase by distillation, or the organic phase may be treated with alkali to effect hydrolysis of such adducts, the ketone separated and recycled and the amino materials recovered.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.