| abstract |
where X is O, S. S -> O, or SO2; n is 0 or 1; m is 0 or 1; the R''s are the same or different and are H or CH3, and one of them can be C2-C9 alkyl, phenyl, C7-C10 phenylalkyl, furyl, thienyl, pyridyl or substituted phenyl or phenylalkyl; when X is S, and m is 0, one R in the group -RCR- can be OCH3; when X is S and m is 1, the R in the group (CHR)mcan be OCH3; and R1is H, C1-C4 alkyl, C3-C5 alkenyl, C3-C5 alkynyl, C3-C6 cycloalkyl, C2-C4 alkoxycarbonyl, trifluoroacetyl, or substituted C1-C4 alkyl where the substituent is C3-C6 cycloalkyl, phenyl or substituted phenyl; and their pharmaceutically suitable salts. The compounds are useful as sedatives; some of them also exhibit antidepressant, antihypertensive and antibacterial activity. The compounds are prepared by cyclizing compounds of formula II wherein R2 is R1 or acyl. The latter compounds are prepared by reacting 4-piperidones with compounds of formula III in the presence of a reducing agent OR WITH COMPOUNDS OF FORMULA VI |