Process for preparing derivatives quanadina.

摘要

The invention relates to guanidine derivatives which are histamine H-2 antagonists and which inhibit gastric acid secretion. According to the invention there is provided a guanidine derivative of the formula I:- IMAGE I in which R1 and R2, same or different, are hydrogen or 1-10C alkyl, 3-8C cycloalkyl or 4-14C cycloalkylalkyl, each alkyl, cycloalkyl or cycloalkylalkyl optionally carrying one or more F, Cl or Br atoms, provided that one of R1 and R2 is halogen substituted, or R2 is hydrogen and R1 is R5-E-W in which W is 2-6C alkylene optionally substituted by 1 or 2 1-4C alkyls, E is O,S or NR6 in which R6 is H or 1-6C alkyl, R5 is H or 1-6C alkyl optionally substituted by 1 or 2 1-4C alkyls, or R5 and R6 are joined to form a pyrrolidine, piperidine, morpholine, piperazine or N-methylpiperazine ring; ring X is a heterocyclic ring as defined in the specification; A is phenylene or 5-7C cycloalkylene, or a 1-8C alkylene into which is optionally inserted one or two groups; D is O or S; and R3 and R4 are hydrogen or a variety of radicals described in the specification: and the pharmaceutically-acceptable acid-addition salts thereof. Manufacturing processes and pharmaceutical compositions are also described.