Method for cyclization to give cephem ring

Claim 1

A process for preparing a compound of the formula ##STR27## wherein A is amino, sulfenylamino or amino substituted by (1) C 1 to C 10 alkanoyl, (2) C 1 to C 5 haloalkanoyl, (3) azidoacetyl, (4) cyanoacetyl, (5) acyl of the formula Ar--CQQ'--CO-- in which each of Q and Q' is hydrogen or methyl and Ar is phenyl, dihydrophenyl or a monocyclic hetero aromatic group containing 1-4 hetero ring atoms selected from the group consisting of nitrogen, oxygen and sulfur, (6) 2-sydnon-3-acetyl, (7) (4-pyridon-1-yl)acetyl, (8) acyl of the formula Ar--G--CQQ'--CO-- in which Ar, Q and Q' are as defined above and G is oxygen or sulfur, (9) acyl of the formula ##STR28## in which Ar is as defined above and T is hydroxy, C 1 to C 10 acyloxy, carboxy, C 2 to C 7 alkoxycarbonyl, C 2 to C 15 aralkoxycarbonyl, C 1 to C 12 aryloxycarbonyl, C 1 to C 7 alkanoyloxy-C 1 to C 3 alkoxycarbonyl, cyano, carbamoyl, sulfo or C 1 to C 7 alkoxysulfonyl, (10) acyl of the formula ##STR29## in which Ar is as defined above and each of W and W' is hydrogen, C 2 to C 7 alkoxycarbonyl, C 3 to C 10 cycloalkyl-C 2 to C 3 alkoxycarbonyl, C 5 to C 8 cycloalkoxycarbonyl, C 1 to C 4 alkylsulfonyl-C 1 to C 4 alkoxycarbonyl, halo C 1 to C 3 alkoxycarbonyl, C 1 to C 15 aralkoxycarbonyl, C 1 to C 10 alkanoyl, C 2 to C 15 aroyl, pyronecarbonyl, thiopyronecarbonyl, pyridonecarbonyl, carbamoyl, guanidinocarbonyl, 3-methyl-2-oxoimidazolidin-1-ylcarbonyl, 3-methanesulfonyl-2-oxoimidazolidin-1-ylcarbonyl, 4-methyl-2,3-dioxopiperazin-1-ylcarbonyl, or 4-ethyl-2,3-dioxopiperazin-1-ylcarbonyl, or W and W' are combined together with the nitrogen atom to which they are attached to form phthalimido, maleimido or enamino derived from C 5 to C 10 acetoacetate, C 4 to C 10 acetacetamide, acetylacetone, acetoacetonitrile or 1,3-cyclopentanedione, (11) acyl of the formula ##STR30## in which Ar is as defined above and E is hydrogen or C 1 to C 5 alkyl, (12) 5-aminoadipoyl, N-protected 5-aminoadipoyl wherein the protecting group is C 1 to C 10 alkanoyl, C 1 to C 10 aralkanoyl, C 2 to C 11 aroyl, C 1 to C 5 haloalkanoyl or C 2 to C 10 alkoxycarbonyl, or carboxy-protected 5-aminoadipoyl wherein the protecting group is C 1 to C 5 alkyl, C 2 to C 21 aralkyl or C 1 to C 10 aryl, (13) acyl of the formula L-O-CO- in which L is C 1 to C 10 hydrocarbyl, (14) diacylimido derived from a C 4 to C 10 polybasic carboxylic acid, (15) C 1 to C 20 hydrocarbyl, (16) C 1 to C 20 hydrocarbylidene, (17) C 2 to C 10 organic silyl, (18) azido, (19) isocyanato, or (20) isocyano, Cob is a carboxylic ester group, Rs is benzothiazol-2-ylthio, thiazol-2-ylthio or acetylthio, Y is C 1 to C 5 alkanoyloxy, C 1 to C 5 alkoxycarbonyloxy, C 7 to C 12 aralkoxycarbonyloxy, C 6 to C 11 aroyloxy, C 1 to C 5 alkanesulfonyloxy, C 6 to C 8 arylsulfonyloxy, cyano, thiocyanato, nitro, nitroso, chlorine, bromine or iodine, and the dotted line represents a 2- or 3- double bond, which comprises reacting a compound of the formula ##STR31## wherein A, COB, RS and Y have the same meanings as above, with a base selected from the group consisting of trimethylamine, triethylamine, tripropylamine, butyldimethylamine, 1-methylpiperdine, N-methylmorpholine, quinuclidine, 4-piperidylpyridine, 1,2,2,6,6-pentamethylpiperidine, 1,4-diazabicyclo[2,2,2]octane, N,N-dimethylaniline, 1,8-bisdimethylaminonaphthalene and diisopropylamine.