Heterocyclic compounds having anti-diabetic activity and their use

A compound of formula (I):

• ##STR714## wherein:
• X represents an azaindolyl, azaindolinyl, imidazopyridyl or imidazopyrimidinyl group which is unsubstituted or is substituted by at least one substituent selected from the group consisting of substituents .alpha. defined below;
• Y represents an oxygen atom or a sulfur atom;
• Z represents a group of formula, (iv) or (v):
• ##STR715## R represents a hydrogen atom, an alkyl group having from 1 to 4 carbon atoms, an alkoxy group having from 1 to 4 carbon atoms, a halogen atom, a hydroxy group, a nitro group, an aralkyl group in which an alkyl group having from 1 to 5 carbon atoms is substituted by an aryl group having from 6 to 10 ring carbon atoms, or a group of formula --NR.sup.a R.sup.b,
• wherein R.sup.a and R.sup.b are the same or different and each represents a hydrogen atom, an alkyl group having from 1 to 8 carbon atoms, an aralkyl group in which an alkyl group having from 1 to 5 carbon atoms is substituted by an aryl group having from 6 to 10 ring carbon atoms, an aryl group having from 6 to 10 ring carbon atoms, an aliphatic carboxylic acyl group having from 1 to 11 carbon atoms, an aliphatic carboxylic acyl group which has from 2 to 6 carbon atoms and which is substituted by an aryl group having from 6 to 10 ring carbon atoms, or an aromatic carboxylic acyl group in which the aryl part has from 6 to 10 ring carbon atoms,
• m is an integer of from 1 to 5;
• each of said substituents a represents an alkyl group having from 1 to 4 carbon atoms, an aryl group having from 6 to 10 carbon atoms, a trifluoromethyl group, an alkylthio group having from 1 to 4 carbon atoms, an alkoxy group having from 1 to 4 carbon atoms, a benzyloxy group, a halogen atom, a hydroxy group, an acetoxy group, a phenylthio group, a nitro group, an aralkyl group, or a group of formula --NR.sup.a R.sup.b, wherein R.sup.a and R.sup.b are as defined above;
• said aryl groups and the aryl parts of said aralkyl groups included in substituents .alpha. are carbocyclic aromatic groups having from 6 to 10 ring carbon atoms and are unsubstituted or are substituted at least one substituent selected from the group consisting of substituents .beta., defined below;
• each of said substituents .beta. represents an alkyl group having from 1 to 4 carbon atoms, an alkoxy group having from 1 to 4 carbon atoms, a halogen atom, a hydroxy group, a nitro group, a phenyl group, a trifluoromethyl group, or a group of formula --NR.sup.a R.sup.b, wherein R.sup.a and R.sup.b are as defined above;
• and salts thereof.