GB1479099A - 6-isocyanato-2,2-dimethyl-3-(5-tetrazolyl)penams - Google Patents

Abstract

1479099 6 - Isocyanato - 2,2 - dimethylpenam derivatives PFIZER Inc 6 Oct 1975 [7 Oct 1974] 40892/75 Heading C2C [Also in Division C3] Novel compounds IIA in which Y 1 has formula (a) or (b) (R 1 is R 2 or a tetrazolylpenam N-protecting group; R 2 is H, alkanoyloxymethyl of 3-8C, 1-alkanoyloxyethyl of 4-9C, phthalidyl or a group (C) R 3 , R 4 and R 5 are H, Cl, Br, F, 1-4C alkyl, 1-40 alkoxy or phenyl) and tertiary amino salts thereof where R 1 or R 2 is H are prepared by reaction of a compound IIB in which Z is H or silyl with phosgene. The compounds IIA may be converted to compounds V in which Y 3 is acyl, carbamyl or substituted carbanyl by reaction with an appropriate acylating agent, ammonia or an appropriate amine. Compounds of formula IIB which are substituted by triphenyl methyl groups (C) are prepared by alkylation of 6-amino-2,2- dimethyl-3-(5-tetrazolyl) penam with an appropriate triphenylmethyl chloride. Compounds IIB where R 1 is H and Y 2 is NH 2 are prepared by a retrograde Michael reaction on a triphenylmethyl derivative of a corresponding compound where R 1 is CH 2 CH 2 R 6 (R 6 is CN, alkoxycarbonyl, phenoxycarbonyl, alkylsulphonyl, phenylsulphonyl or a sulphamyl group). Compound VIII (in which G is -COOR 7 , -SO 2 R 7 , -CH 2 CH 2 R 6 or -CHW 1 W 2 ; R 7 is 1-6C alkyl, benzyl or optionally substituted phenyl; W 1 is optionally substituted phenyl, furyl or trienyl; and W 2 is H, alkyl or W 1 ) are prepared from 6-(triphenylmethylamino)penicillanic acid by reaction with NH 2 CH 2 CH 2 R 6 , H 2 N-CHW 1 W 2 , The compounds VIII may be reacted with phosgene to give the appropriate imidoyl chlorides which are then treated with a source of azide ions to give the compounds IX.