Phenyl-2-(2-pyrrolidin-1-ylethyl)-3,4 dihydroisoquinoline-1(2H)-one and process for preparation and pharmaceutical composition thereof

Abstract

The present invention provides a compound of formula I wherein X1 is (CR4R5)p, CO or O; X2a and X2b are taken together to form =O; m is 0, 1 or 2; n is 2, 3 or 4; p is 0, 1 or 2; q is 1,2 or 3; R1 and R2 are each independently H, halogen or an alkyl or haloalkyl group each group optionally substituted; R3 is NR6R7 or a cycloheteroalkyl, aryl or heteroaryl group each group optionally substituted with the proviso that when X1 is O then R3 must be other than NR6R7; and when X2a and X2b are taken together to form =O and p is 0, then R3 is not quinoxalinyl¬2(1H)-one or an optionally substituted 1,3,4-oxadiazole; Or a stereoisomer or tautomer thereof, process of preparation and pharmaceutical composition comprising the compound, useful in modulation of the histamine-3 (H3) receptor and treatment of a variety of central nervous system disorders related to or affected by H3 receptor.