PROCESS FOR PREPARING NEW HISTAMINE H.SUB.2 -ANTAGONISTS

摘要

11727. The invention provides new histamine H2antagonist compounds of Structure 1 (1) in which R1 is hydrogen, lower alkyl, lower alkoxy, hydroxy, halogen, trifluoromethyl, nitro, amino, lower alkylamino, lower alkanoylamino, di(lower alkyl)amino or cyano; R2 is in the 3-, 4- or 5- position and is hydrogen, or R2 is lower alkyl substituted by amino, lower alkylamino, di(lower alkyl)amino, N-piperidino or N-pyrrolidino, or R2 is ethoxy or propoxy .omega.-substituted by amino, lower alkylamino, di(lower alkyl)amino, N-piperidino or N-pyrrolidino; Y is methylene or oxygen and X is methylene or sulphur provided that one or two of the groups X and Y is methylene; Z is hydrogen or lower alkyl; A is C1-C5 alkylene or -(CH2)pW-(CH2)q- where W is oxygen or sulphur and p and q are such that their sum is from 1 to 4, and B is hydrogen, methyl C3-C6 cycloalkyl, a heteroaryl group optionally substituted by one or more of the groups lower alkyl, lower alkoxy, halo, hydroxy and amino, or B is a naphthyl, 6-(2,3-dihydro-1,4-benzodioxinyl), a 4- or 5-(1,3-benzodioxolyl) group, or a phenyl group optionally substituted with one or more lower alkyl, lower alkoxy, halogen, aryl(lower alkoxy), hydroxy, 11727. lower alkoxy-lower alkoxy, trifluoromethyl, di(lower alkyl)amino, phenoxy, halophenoxy, lower alkoxyphenoxy, phenyl, halophenyl or lower alkoxyphenyl groups and pharmaceutical compositions containing them. A compound of Structure 1 can be prepared by reacting a compound of Structure 3 in which Q is nitroamino, loweralkylthio, benzylthio or halogen with an amine of Structure 2, in which (2) (3) R3 is in the 3-, 4- or 5- position and is hydrogen, lower alkyl substituted by a group R4, or is R4CH2CH2O- or R4CH2CH2CH2O-, where R4 is di(lower alkyl)amino, N-piperidino, N-pyrrollidino, a protected amino group or a protected lower alkylamino group, and where necessary any amino-protecting group present in the substituent R3 is removed.