Cyclization process for making oxazolikinones
US5688962A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 16, 1996 |
| Grant date | Nov 18, 1997 |
| Priority date | — |
| Expiry date | May 16, 2016 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07D263/28
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A process for the synthesis of a compound of general formula II: ##STR1## wherein: R.sup.2 and R.sup.3 are each independently hydrogen or C.sub.1 -C.sub.4 alkyl; A is an aromatic or heteroaromatic ring system optionally substituted with one or more substituents as defined herein; and in which any ring nitrogen atom may be quaternised or oxidised; alternatively, any two substituents of the group A may combine to form a fused 5- or 6-membered saturated or partially saturated carbocyclic or heterocyclic ring in which any carbon or quaternised nitrogen atom may be substituted with any of the groups defined herein for A or in which a ring carbon atom may be oxidised; the process comprising cyclising a compound of general formula VII: ##STR2## wherein A, R.sup.2 and R.sup.3 are as defined for general formula II, R.sup.20 is hydrogen, benzyl or benzyl substituted with up to five substituents selected from halo, C.sub.1 -C.sub.6 alkyl, O(C.sub.1 -C.sub.6 alkyl) or nitro and R.sub.21 is C.sub.1 -C.sub.8 alkyl, benzyl or benzyl substituted with up to five of the substituents mentioned above for R.sup.20.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.