HETEROCYCLIC DERIVATIVES

摘要

The invention relates to compounds of the general formula (I) and physiologically acceptable salts, hydrates and bio-precursors thereof in which R1 represents C1-14 alkyl, cycloalkyl, aralkyl, trifluoroalkyl, heteroalkyl, alkenyl, alkynyl, or alkyl substituted by hydroxy, alkoxy, amino, alkylamino, dialkylamino or cycloalkyl; and R2 represents hydrogen or a C1-4 alkyl group; or R1 and R2 together with the nitrogen atom to which they are attached form a 5-10 membered ring which may be saturated or may contain at least one double bond, may be unsubstituted or may be substituted by one or more C1-3 alkyl groups or a hydroxy group and/or may contain another heteroatom selected from oxygen and sulphur; Alk represents a straight or bramches C1-6 alkylene chain. Q represents a furan or thiophen ring in which incorporation into the rest of the molecule is through bonds at the 2- and 5-positions the furan or thiophen ring optionally bearing a further substituent R4 adjacent to the group R1R2N-Alkyl-; or Q represents a thiophen ring in which incorporation into the rest of the molecule is through bonds at the 2- and 4-positions, the thiophen ring optionally bearing a further substituent R4 adjacent to the group R1R2NAlk with the proviso that when the group R1R2NAlk is in the 4-position then the group R4 is in the 5-position; or Q represents a benzene ring in which incorporation into the rest of the molecule is through bonds at the 1- and 3- or 1- and 4-positions; R4 represents halogen or C1-4 alkyl which may be substituted by hydroxy or C1-4 alkoxy; R3 represents hydrogen, alkyl, alkenyl, aralkyl, C2-6 alkyl substituted by hydroxy, alkoxy, or C1-4 alkanoyloxy; X and Y, which may be the same or different, each represent oxygen, sulphur, methylene or a bond; n represents zero, 1, 2, or 3 and m represents an interger from 2 to 5 with the provisos that (a) the total number of atoms in the chain X(CH2)nY(CH2)m is an integer from 3 to 8 and (b) when X and Y represent oxygen or sulphur then n is 2 or 3. The compounds show pharmacological activity as selective histamine H2-antagonists.