Process for the preparation of substituted quinazoline-2,4,-diones
US5539114A · kind A · utility
4Cited by
5References
14Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Nov 15, 1994 |
| Grant date | Jul 23, 1996 |
| Priority date | — |
| Expiry date | Nov 15, 2014 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07D239/96
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A process for the preparation of quinazoline-2,4-diones of the formula (I) ##STR1## in which R.sup.1 is aryl and R.sub.2, R.sup.3, R.sup.4, and R.sup.5 independently of one another are halogen, alkyl, alkoxy or hydrogen, by reacting anthranilic acid esters of the formula (II) ##STR2## in an aprotic reaction medium with aryl isocyanates R.sup.1 --N.dbd.C.dbd.O to give N-arylcarbamoyl-anthranilic acid esters of the formula (III) ##STR3## and cyclizing these in the presence of a base selected from the group of alkali metal or alkaline earth metal alkoxides, amides, hydrides or tetraalkylammonium hydroxides.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.