Abstract: Pyrrole derivatives of formula: ##STR1## in which R.sub.1 represents a hydrogen or halogen atom, a linear or branched C.sub.1-6 alkyl group, a C.sub.3-6 alkenyl group, a C.sub.1-4 alkoxymethyl group, benzyl, a phenyl group optionally substituted by one or more halogen atoms or alkyl radicals, a CO.sub.2 R group in which R represents a linear or branched C.sub.1-4 alkyl radical, phenyl or benzyl, or a CONR'R" group in which R' and R" each represent, independently of one another, a hydrogen atom or a linear or branched C.sub.1-4 alkyl radical,R.sub.2 represents a hydrogen or halogen atom or a linear or branched C.sub.1-4 alkyl group,and R.sub.3 represents a 4,5-dihydro-1H-imidazol-2-yl or 1H-imidazol-4-yl group, and their addition salts with pharmaceutically acceptable acids are useful in therapeutics as .alpha..sub.2 -antagonists, and .alpha..sub.1 -agonists.

Abstract: [(1-Arylpyrrolidin-2-yl)methyl]piperazine compounds corresponding to the formula ##STR1## in which Z denotes a group of formula N-R.sub.1 in which R.sub.1 is either a hydrogen atom or a C.sub.1-3 alkyl group or a group of formula Ar--C.sub.n H.sub.2n in which n denotes 0, 1 or 2 and Ar denotes a phenyl group optionally substituted by one or more halogen atoms and/or C.sub.1-3 alkyl or C.sub.1-3 alkoxy radicals, or a group of formula COR.sub.2 in which R.sub.2 denotes the CH.sub.3, C.sub.6 H.sub.5, CH.sub.2 C.sub.6 H.sub.5 or OC.sub.2 H.sub.5 group and their salts of addition to pharmaceutically acceptable acids. The compounds are useful for the treatment of neurological disorders.

Abstract: A compound which is a pyrido[3,4-b]derivative of formula (I) ##STR1## in which R is a hydrogen atom or an alkyl carbonyl, arylalkylcarbonyl or arylcarbonyl group of formula COR.sub.1 wherein R.sub.1 is a C.sub.1 -C.sub.6 alkyl group, a benzyl group or a phenyl group unsubstituted or substituted with 1 to 3 substituents chosen from halogen atoms and trifluoromethyl, C.sub.1 -C.sub.3 alkyl and C.sub.1 -C.sub.3 alkoxy groups or R is an alkoxycarbonyl or benzyloxycarbonyl group of formula COOR.sub.2 wherein R.sub.2 is a C.sub.1 -C.sub.6 alkyl group or a benzyl group, or R is a substituted aminocarbonyl group of formula CONHR.sub.3 wherein R.sub.3 is a C.sub.1 -C.sub.6 alkyl group or a phenyl group, or R is an arylsulphonyl group of formula SO.sub.2 R.sub.4 wherein R.sub.4 is a phenyl group, or a pharmacologically acceptable acid addition salt thereof useful for treating hypertension, depressive state or anxiety state.

Abstract: Derivatives of formula (I) ##STR1## in which X denotes a hydrogen or halogen atom, an alkoxy radical, an alkyl radical or an allyloxy radical, and R denotes a linear or branched alkyl radical, a cycloalkylalkyl radical, an alkenyl radical, an arylalkyl radical which can bear one or more substituents chosen from halogen atoms and methyl, methoxy and methylenedioxy radicals, or alternatively an optionally substituted phenyl radical, as well as the addition salts thereof with pharmaceutically acceptable acids produce an .alpha..sub.2 -receptor antagonist effect.

Abstract: Indole derivatives, in the form of racemates or optically active isomers, of the formula (I) ##STR1## in which R.sub.1 is a hydrogen atom, a linear or branched (C.sub.1-6) alkyl group, a (C.sub.3-6) cycloalkyl-(C.sub.1-4) alkyl group, a (C.sub.2-6) alkenyl group, the naphthylmethyl group, the phenethyl group or a benzyl group optionally substituted by one or more halogen atom or methyl, methoxyl or methylenedioxy group and R.sub.2 is H or a (C.sub.1-4) alkyl or allyl group, and their pharmaceutically acceptable salts; are .alpha..sub.2 -antagonists and useful for the treatment of depression, hypotension, post-operative paralytic ileum, asthma and obesity.

Abstract: Compounds of the general formula (I) ##STR1## in which R.sub.1 is a hydrogen atom or a (C.sub.1 -C.sub.4)-alkyl, benzyl, phenethyl or methoxy group and R.sub.2 is a hydrogen atom or a methyl group, and their addition salts with pharmaceutically acceptable acids are useful, as such or in pharmaceutical compositions containing them in association with excipients, as .alpha..sub.2 -antagonists.