Total synthesis of 7-oxo-4-thia-1-azabicyclo-[3,2,0]-heptane-2-carboxyl derivatives useful as .beta.-lactamase inhibitors and antibacterial agents
US4269771A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 13, 1979 |
| Grant date | May 26, 1981 |
| Priority date | — |
| Expiry date | Nov 13, 1999 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07F9/568
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A process is disclosed for the preparation of compounds of formula I: ##STR1## wherein R is hydrogen, lower alkyl, trichloroethyl, benzyl, p-nitrobenzyl, acetoxymethyl, pivaloyloxymethyl, phthalidyl, or a --CH(CH.sub.3)OCOOEt group; PA1 R.sup.1 is --CH.sub.2 OH, --CHO, --CH.sub.2 SH, --CH.sub.2 NH.sub.2, --CH.sub.2 OCOR.sup.2, --COOR.sup.2, --CH.sub.2 NHCOR.sup.2, --CH.sub.2 OR.sup.3, or --CH.sub.2 SR.sup.4 where R.sup.2 is a lower alkyl, aryl or a heterocyclic ring, R.sup.3 is a lower alkyl, benzyl, or trityl, and R.sup.4 is a five- or six-member heterocyclic ring containing one or more heteroatoms, PA1 which comprises reacting a 4-acetoxy azetidinone with a .beta.-thioketoester to form a mixture, reacting said mixture with thionyl chloride followed by reaction with a phosphine and a base, ozonolyzing and heating to obtain the compounds of formula I.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.