Tricyclic oxime ethers

A compound selected from those of formula (I):

• ##STR140## wherein R.sub.1 is selected from:
• hydrogen,
• alkyl,
• alkenyl,
• cycloalkyl,
• cycloalkyl in which the alkyl chain is straight or branched and has 1 to 4 carbon atoms inclusive,
• hydroxy,
• alkoxy,
• unsubstituted or substituted phenyl,
• unsubstituted of substituted phenylalkyl in which the alkyl chain is straight or branched and has 1 to 4 carbon atoms inclusive,
• unsubstituted or substituted phenoxy, and
• unsubstituted or substituted phenylalkoxy in which the alkyl chain is straight or branched and has 1 to 4 carbon atoms inclusive,
• or R.sub.1 forms with R.sub.2 and the chain ##STR141## carrying them a nitrogen-containing ring system having 5 to 8 ring members inclusive,
• R.sub.2 and R.sub.3 are each selected, independently of the other, from:
• hydrogen,
• alkyl,
• alkenyl,
• cycloalkyl,
• unsubstituted or substituted indanyl,
• cycloalkylalkyl in which the alkyl chain is straight or branched and has 1 to 4 carbon atoms inclusive,
• unsubstituted or substituted phenyl, and
• unsubstituted or substituted phenylalkyl in which the alkyl chain is straight or branched and has 1 to 4 carbon atoms inclusive,
• or R.sub.2 and R.sub.3 form together with the nitrogen atom carrying them a heterocyclic system selected from:
• ##STR142## wherein:
• m is 0, 1, 2, 3, or 4,
• n is 0, 1, or 2,
• Y' is selected from oxygen, sulfur and ##STR143## R.sub.4 being selected from:
• hydrogen,
• alkyl, and
• unsubstituted or substituted --(CH.sub.2).sub..sigma. -phenyl, wherein .sigma. is 0, 1, 2, 3, or 4,
• x and y are identical or different and are 0, 1, 2, 3, or 4,
• A represents:
• a group of formula (.alpha.):
• ##STR144## and thus forms with the heterocyclic system carrying it a thieno[2,3-d]pyrrolo[1,2-a]pyrrole of the formula (I.sub..alpha.):
• ##STR145## wherein R.sub.1, R.sub.2, R.sub.3, x, and y are as defined hereinbefore and R.sub.5 and R.sub.6, which are identical or different, each represents, independently of the other, a group selected from:
• hydrogen,
• alkyl,
• hydroxy,
• alkoxy,
• halogen,
• trifluoromethyl,
• alkoxycarbonyl,
• unsubstituted or substituted --(CH.sub.2).sub.p -phenyl wherein p is 0, 1, 2, 3, or 4, and
• unsubstituted or substituted --O--(CH.sub.2).sub.p' -phenyl wherein p' is 0, 1, 2, 3, or 4,
• a group of formula (.beta.):
• ##STR146## and thus forms with the heterocyclic system carrying it a thieno[3,2-d]pyrrolo[1,2-a]pyrrole of the formula (I.sub..beta.):
• ##STR147## wherein R.sub.1, R.sub.2, R.sub.3, R.sub.5, R.sub.6, x and y are as defined hereinbefore,
• a group of formula (.gamma.):
• ##STR148## and thus forms with the heterocyclic system carrying it a pyrrolo[1,2-a]indole of the formula (I.gamma.):
• ##STR149## wherein R.sub.1, R.sub.2, R.sub.3, R.sub.5, R.sub.6, x and y are as defined hereinbefore,
• their cis or trans isomers in respect of the oxime ether,
• their enantiomers or diastereoisomers, and
• their hydrates and/or pharmaceutically-acceptable addition salts with an acid or a base,
• it being understood, unless specified otherwise, that:
• the terms "alkyl" and "alkoxy" represent a straight-chain or branched group having 1 to 6 carbon atoms inclusive,
• the term "alkenyl" represents a straight-chain or branched unsaturated group having 2 to 6 carbon atoms inclusive,
• the term "cycloalkyl" represents a carbon ring system having 3 to 8 ring members inclusive,
• the expressions "substituted indanyl", "substituted phenyl", "substituted phenoxy", "substituted phenylalkyl", "substituted --(CH.sub.2).sub..sigma. -phenyl", "substituted --(CH.sub.2).sub.p -phenyl", substituted "--O--(CH.sub.2).sub.p' -phenyl" and "substituted phenylalkoxy" denote that the phenyl radical is substituted by one or more identical or different substituents selected from alkyl, alkoxy, hydroxy, halogen, trifluoromethyl, nitrile and nitro.