Colin Bennion, Roger C. Brown, Anthony R. Cook, Carol N. Manners, David W. Payling,* and David H. Robinson* ... Departments of Medicinal Chemistry and Physical Chemistry, Fisons plc, Pharmaceutical Division, Research and Development Laboratories, Bakewell Road, Loughborough, Leicestershire LE11 ORH, UK. Received April 2, 1990 ... Two novel series of dihydrothiadiazole ring containing inhibitors of angiotensin converting enzyme have been ...