6-Alkoxylated-6-acylamidopenicillanic acids and 7-alkoxylated-7-acylamidocephalosporin acids and esters thereof, are provided by reacting a 6-acylamidopenicillanic acid ester or a 7-acylamidocephalosporin ester under anhydrous conditions at -90.degree. C. to -15.degree. C. with an alkali metal salt of a lower alkyl alcohol in the presence of an excess of the corresponding alcohol to produce, in situ, the anionic form of the antibiotic which on halogenation with a positive halogen compound, e.g. t-butyl hypochlorite, yields the compound of the invention. Compounds of the invention, e.g. 6-methoxy-6-phenoxy-acetamidopenicillanic acid and 7-methoxy-7-[2-(2-thienyl)acetamido]cephalosporanic acid are useful antibiotics.
                            本发明提供了6-烷氧基化-6-酰胺基青霉烷酸和7-烷氧基化-7-酰胺基
头孢菌素酸及其
酯类。方法是在无
水条件下,将6-酰胺基青霉烷酸酯或7-酰胺基
头孢菌素酸酯与低级烷基醇的碱
金属盐在过量相应醇的存在下,在-90℃至-15℃反应,产生抗生素的阴离子形式,然后用正卤素化合物(例如叔丁基
次氯酸酯)卤化,得到本发明的化合物。本发明的化合物,例如6-甲氧基-6-苯氧基乙酰胺基青霉烷酸和7-甲氧基-7-[2-(2-
噻吩基)乙酰胺基]
头孢菌素酸是有用的抗生素。