Carbazolone derivatives
US5416221A · kind A · utility
Inventors
Key dates
| Filing date | Oct 13, 1993 |
| Grant date | May 16, 1995 |
| Priority date | — |
| Expiry date | Oct 13, 2013 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07D209/88
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
The invention relates to carbazolone derivatives of the formula ##STR1## wherein A stands for a group of formula EQU --CH.sub.2 --R (V), PA1 wherein R means a hydroxyl or 2-methyl-1H-imidazol-1-yl group; PA1 B represents a group of formula ##STR2## wherein R.sub.1 means hydrogen or a methyl or ethyl group; or A and B together form a group of formula ##STR3## wherein R.sub.2 means a methyl or ethyl group; or A and B together form a group of formula ##STR4## The above compounds are useful intermediates in the synthesis of ondansetron of formula ##STR5## chemically 9-methyl-3-[(2-methyl)-1H-imidzol-1-yl)methyl]1,2,3,9-tetrahydro-4H-carbaz ol-4-one. The invention further relates to a novel process for the preparation of compounds of the formula (I), wherein A and B are the same as in formula (I) but B may be also hydrogen. Thus, this novel process is suitable for the preparation of ondansetron itself.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.