1,2,5-THIADIAZOL-3,4-DIAMINE DERIVATIVES AS HISTAMINE H.SUB.2-RECEPTOR ANTAGONISTS

摘要

11871 Compounds of the formula (I) : (I) or pharmaceutically acceptable salts are described, wherein R1 and R2 are independently hydrogen or C1-6alkyl, or R1 and R2 together represent - (CH2)q- wherein q is 4 to 7, to form together with the nitrogen atom to which they are attached, a 5-8 membered saturated ring, optionally substituted by C1-6alkyl; X is -CH2- or sulphur; n is 2 or 3, or if X is -CH2- n can also be 1; p is 1 or 2; and R3 is hydrogen, C1-6alkyl, C3-6alkenyl or C3-6alkynyl (wherein the unsaturated bond is not adjacent to the -NH-moiety). The compounds are histamine H2-receptor antagonists and are useful in treating diseases mediated via histamine H2-receptors. Processes for their preparation, pharmaceutical compositions containing them and methods of use are described.