PIPERAZINYL PYRIDINES AND PIPERINYL-IMIDAZOLES AND PHARMACEUTICAL COMPOSITIONS; INTERMEDIATES

A compound of the formula: or a pharmaceutically acceptable salt thereof, wherein is selected from (a) a 3- or 4-pyridinyl group optionally substituted by one or two substituents each independently selected from C1-C4 alkyl and amino, (b) a 2-pyridinyl group substituted by an amino group, (c) a 2-imidazolyl group optionally substituted by one or two C1-C4 alkyl groups and (d) a 2-, 3- or 4-pyridinyl group substituted by a nitro group, or an N-oxide thereof, or a 2-, 3- or 4-pyridinyl group substituted by a group of the formula -NHCOO(C1-C4 alkyl); R is selected from (a) -NHSO2R where R is C1-C4 alkyl, C3-C7 cycloalkyl or -NR R where R and R are each independently M or C1-C4 alkyl, (b) -SO2NR R where R and R are as defined above, (c) nitro, (d) amino and (e) acetamido; and X is a group of the formula -(CH2)m- where m is an integer of from 1 to 4, -CO(CH2)n- or -CH(OH)(CH2)n- where n is 1, 2 or 3.