| 摘要 |
<p>Compounds of the formula (I):- <IMAGE> and physiologically acceptable salts, hydrates and bioprecursors thereof have been found to show pharmacological activity as selective histamine H2-antagonists. In formula (I> R1 represents hydrogen, C1-14 alkyl, cycloalkyl, alkenyl, aralkyl, heteroaralkyl, trifluoroalkyl or substituted alkyl; and R2 represents hydrogen or C1-4 alkyl; or R1 and R2 together complete an optionally substituted 5 to 10 membered ring; Alk represents C1-3 alkylene; Q represents a furan or thiophene bonded via the 2- and 5- positions, the furan or thiophene ring optionally bearing a further substituent R4 adjacent to the group R1R2N-Alk-; or Q represents a thiophene ring bonded via the 2- and 4- positions, the thiophene ring optionally bearing a further substituent R4 adjacent to the group R1R2NAlk with the proviso that when the group R1R2 NAlk is in the 4- position then the group R4 is in the 5-position; or Q represents a benzene ring bonded via 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; X represents oxygen, sulphur-, -NH-, methylene or a bond; Y represents oxygen, sulphur, methylene or a bond; n represents zero, 1, 2 or 3 and m is an integer 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, (b) when X and Y represents oxygen or sulphur then n is 2 or 3, (c) when X represents -NH- then Q is a benzene ring and Y represents methylene or a bond, and (d) when Q represents a benzene ring, X represents oxygen, and n represents 1, then m may additionally represent 1 and Y may additionally represent -CHOR14 where R14 represents hydrogen or acyl; and R3 represents hydrogen, alkyl, alkenyl, aralkyl, or C2-6 alkyl substituted by hydroxy or alkoxy; either A represents N and B min represents CR5; or A represents CR5 and B represents N; and R5 represents one of various defined substituents.</p> |
