Process for the preparation of nitroguanidine derivatives
US6518433B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 18, 2000 |
| Grant date | Feb 11, 2003 |
| Priority date | — |
| Expiry date | Sep 18, 2020 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07D213/61
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A process for the production of a compound of formula (I) whereinR1 is hydrogen or C1-C4-alkyl;R2 is hydrogen, C1-C6-alkyl, C2-C6-alkenyl, C2-C6-alkinyl, C3-C6-cycloalkyl or a radical —CH2B;A is selected from the group consisiting of 2-chloropyrid-5-yl, tetrahydrofuran-3 -yl, 5-methyl-tetrahydrofuran-3-yl or 2-chlorothiazol-5-yl; andB is phenyl, 3-pyridyl or thiazolyl, which are optionally substituted by one to three substituents selected from the group consisting of C1-C3-alkyl, C1-C3-halogenalkyl, cyclopropyl, halogencyclopropyl, C2-C3-alkenyl, C2-C3-alkinyl, C1-C3-alkoxy, C2-C3-halogenalkenyl, C2-C3-halogenalkinyl, C1-C3-halogenalkoxy, C1-C3-alkylthio, C1-C3-halogenalkylthio, allyloxy, propargyloxy, allylthio, propargylthio, halogenallyloxy, halogenallylthio, halogen, cyano or nitro;and optionally the possible E/Z isomers, E/Z isomeric mixtures and/or tautomers thereof, respectively in free form or in salt form;characterised in that a compound of formula (II) whereinR1, R2 and A have the same significances as in formula (I), andX is O or S;is hydrolysed with a strong acid at a pH below 2; at a temperature between 50 and 100° C; and in a solvent selected from the group …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.