| abstract |
A3(2H)pyridazinone of the formula:n nwherein R 1 is hydrogen or C 1 -C 5 alkyl; R 2 is hydrogen, C 1 -C 8 -alkyl, chlorine or bromine; A is -NR 3 - or -0-; X is -(CH 2 ) n- , -CH(OR 4 )-, -CO- or a single bond; when X is -(CH 2 ) n - or a single bond, B is -O-, -S-, -NH-, -OS0 2 -, or -OCO- or a single bond, when X is -CH(OR 4 )-, B is -0-, -S-, -NH- or -OS0 2 -, and when X is -CO-, B is -O- or -S-; and each of Y 1 , Y 2 and Y 3 which may be the same or different, is hydrogen, C 1 -C 8 alkyl, C 2 -C 8 alkenyl, halogen, -OR S , -C0 2 R 6 , -CH=CHCO 2 R 7 , -CN,n n-CON(R 8 )(R 9 ), -COR 10 , or two of Y 1 , Y 2 and Y 3 togetherformn nand a pharmaceutically acceptable salt thereof. |