Process for the production of 1-substituted-3-hydroxy-5-chloro-1,2,4-triazoles
US4252965A · kind A · utility
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3Claims
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Key dates
| Filing date | Jul 5, 1979 |
| Grant date | Feb 24, 1981 |
| Priority date | — |
| Expiry date | Jul 5, 1999 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07D249/12
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
An improved process is provided for the production of 1-substituted-3-hydroxy-5-chloro-1,2,4-triazoles which involves reacting in dilute solution a 1-substituted-1-cyanohydrazine with phosgene in tetrahydrofuran as the specific inert solvent, treating the reaction mixture with anhydrous ammonia to form an ammonium salt of the 1,2,4-triazole, said ammonium salt being insoluble in tetrahydrofuran, and liberating from said isolated salt the 1,2,4-triazole in yields from about 85 to 92% of theory and in very pure state by treating said salt with an acid. The 1,2,4-triazoles are valuable intermediates in the manufacture of pesticides.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.