Process for preparation of 7-alkoxy-3-chloromethylcephems

A process for preparing a 3-chloromethylcephem compound of the formula ##STR15## which comprises reacting a compound of the formula ##STR16## with from about 1 to about 5 equivalents of an alkali metal salt of a primary C.sub.1 -C.sub.7 alcohol of the formula R.sub.1 'OH in the presence of from about 1 to about 5 equivalents of tert-butyl hypochlorite in an inert organic solvent at a temperature of about -80.degree. to about 0.degree. C., wherein in the above formulae

• q is 1 or 0;
• R is a carboxylic acid protecting group;
• R is a carboxylic acid protecting group;
• R.sub.1 ' is primary C.sub.1 -C.sub.6 alkyl or benzyl;
• and
• R.sub.2 is an amido group of the formula ##STR17## wherein R.sub.3 is a. hydrogen, C.sub.1 -C.sub.3 alkyl, halomethyl, 3-(2-chlorophenyl)-5methylisoxazol-4-yl or 4-protected amino-4-protected carboxybutyl;
• b. benzyloxy, 4-nitrobenzyloxy, 2,2,2-trichloroethoxy, tert-butoxy, or 4-methoxybenzyloxy;
• c. the group --R" wherein R" is 1,4-cyclohexadienyl, phenyl or phenyl substituted with 1 or 2 substituents independently selected from the group consisting of halo, protected hydroxy, nitro, cyano, trifluoromethyl, C.sub.1 -C.sub.3 alkyl, and C.sub.1 -C.sub.7 alkoxy;
• d. an arylalkyl group of the formula
• R"--(O).sub.m --CH.sub.2 --
• wherein R" is as defined above, and m is 0 or 1;
• e. a substituted arylalkyl group of the formula ##STR18## wherein R'" is R" as defined above, 2-thienyl or 3-thienyl, and W is protected hydroxy or protected amino;
• or
• f. a heteroarylmethyl group of the formula
• R""--CH.sub.2 --
• wherein R"" is 2-thienyl, 3-thienyl, 2-furyl, 2-thiazolyl, 5-tetrazolyl, 1-tetrazolyl;
• or 4-isoxazolyl.