7-(D-.alpha.-Hydroxy-2-arylacetamido)-3-(2-carboxyalkyl-2,3-dihydro-s-triaz olo[4,3-b]pyridazin-3-on-6-ylthiomethyl)-3-cephem-4-carboxylic acids and derivatives containing blocking groups on the .alpha.-hydroxy group and their nontoxic, pharmaceutically acceptable salts are valuable as antibacterial agents and are particularly valuable as therapeutic agents in poultry and in animals, including man, in the treatment of infectious diseases caused by many Gram-positive and Gram-negative bacteria. A preferred compound is 7-(D-mandelamido)-3-(2-carboxyalkyl-2,3-dihydro-s-triazolo[4,3-b]pyridazin -3-on-6-ylthiomethyl)-3-cephem-4-carboxylic acid.
7-(D-.alpha.-羟基-2-芳基乙酰胺基)-3-(2-羧基烷基-2,3-二氢-s-三唑并[4,3-b]
吡嗪-3-酮-6-基
硫甲基)-3-头孢烯-4-
羧酸及其α-羟基上含有阻断基的衍
生物和其无毒、药学上可接受的盐在抗菌剂中具有价值,特别在家禽和动物以及人类感染的多种革兰氏阳性和阴性细菌引起的感染疾病的治疗中具有重要价值。首选化合物是7-(D-曼德酰胺基)-3-(2-羧基烷基-2,3-二氢-s-三唑并[4,3-b]
吡嗪-3-酮-6-基
硫甲基)-3-头孢烯-4-
羧酸。