A series of N-substituted carbamates V-XIII was prepared by reactions of 6,11-dihydrodibenzo[b,e]thiepin-11-ol (I) with carbamates H2NCOOR in acetic acid. Whereas the Leuckart reaction of dibenzo[b,e]thiepin-11(6H)-one yielded 9-formamido-10-methylene-9,10-dihydroanthracene (XVIII), a satisfactory method for preparing the amine III was found in heating the carbamate V with 2-aminoethanol to 170°C. Reactions of the amine III with isocyanates gave most of the disubstituted ureas XX-XXV. The expected anticonvulsant activity was found only in high doses with compounds IX, XII, XV, XX, XXI and XXXIII.

Reaction of N-(1-(2-phenylethyl)-4-piperidinyl)propionanilide (I) with phosphorus pentasulfide gave the thioamide VI. Acylation of N-(1-(2-phenylethyl)-4-piperidinyl)aniline with 2-(methoxy)acetic and 2-(methylthio)acetic anhydrides afforded the amides II and III. Treatment of 4-anilino-1-benzylpiperidine-4-methanol with thionyl chloride gave the spirocyclic sulfurous acid ester amide XIV. Reduction of the hydrochloride of ethyl 3-(1-ethoxycarbonyl-4-phenylimino-3-piperidinyl)propionate (XXII) with sodium cyanoborohydride gave the perhydro-1,6-naphthyridine derivative XIX, a model compound in the synthesis of the cyclic analogue of fentanyl (I). Ethyl 4-anilino-1-(2-phenylethyl)-1,2,3,6-tetrahydropyridine-3-carboxylate (XXIX) hydrochloride, obtained by reaction of ethyl 4-oxo-1-(2-phenylethyl)piperidine-3-carboxylate hydrochloride with aniline, was reduced with lithium aluminium hydride to 4-anilino-1-(2-phenylethyl)piperidine-3-methanol (XXXI). 1-Methyl- and 1-benzyl-4-piperidone were reacted with 4-cyclopropylphenylmagnesium bromide and the tertiary alcohols XXXVII and XXXVIII obtained were acylated with propionyl chloride to give the esters XXXIX and XL. The piperidine derivatives XLI, XLVI and XLVIII were prepared as potential neurotropic agents. Alkylation of 8-hydroxy-6,11-dimethyl-1,2,3,4,5,6-hexahydro-2,6-methano-3-benzazocine (XLIX) with 2-(2-chloroethyl)-1,3-dioxane and -1,3-dioxolane resulted in the 6,7-benzomorphan derivatives L and LI. Out of the compounds prepared, only the closest fentanyl analogues II, III, and VI showed very strong analgetic activity.

Ethyl (2-oxo-1-pyrrolidinyl)acetate was transformed by ester exchange to the 2-dimethylaminoethyl ester VI which was converted to the choline iodide ester VII. The mixed anhydride of (2-oxo-1-pyrrolidinyl)acetic acid and monoethyl carbonate was reacted with ethyl aminoacetate to give the ester VIII which was transformed on the one hand to the amide IX, and to the 2-dimethylaminoethyl ester X on the other. Reaction of the latter with methyl iodide afforded a further choline iodide ester XI. Reactions of (2-oxo-1-pyrrolidinyl)acetyl chloride with 4-chloroaniline and 3-aminopyridine gave the amides XII and XIV. The anilide XIII was obtained from 2-(2-oxo-1-pyrrolidinyl)butyric acid and 4-chloroaniline by means of dicyclohexylcarbodiimide. The benzo analogue (XV) of piracetam (I) was synthesized from oxindole via the ester XVI. The anilide XII (V⁄FB-16 536) was found to potentiate significantly the anticonvulsant effect of diazepam in mice, to prolong the survival time of mice under conditions of nitrogen anoxia, and to prolong significantly the duration of the "gasping reflex" in mice.

The mixed anhydride of 5-(aminosulfonyl)-2-methoxybenzoic acid (VII) and monoethyl carbonate reacted with benzylamine, 1-methylpiperazine, and 1-benzylpiperazine to give the 5-(aminosulfonyl)-2-methoxybenzamides II, IV, and V. Heating the ethyl ester X with 4-amino-1-methyl-piperidine resulted in the amide III. Reaction of 5-(chlorosulfonyl)-2-methoxybenzoyl chloride (XI) with 1-benzylpiperazine afforded 5-(4-benzylpiperazinosulfonyl)-2-methoxybenzoic acid 4-benzylpiperazide (VI). Compounds II-VI are analogues of the antidopaminergic and antiemetic agent sulpiride (I) but only benzylpiperazides V and VI showed indications of psychotropic activity of the neuroleptic type.

The ketone XIII, obtained by Friedel-Crafts reaction of toluene with homoveratroyl chloride, was converted by the Leuckart reaction to the formamido derivative IXb which was used as the starting product for the synthesis of amines IIIb-Vb. Reduction of the ketone XIII gave the alcohol XVI which was treated with hydrogen chloride and afforded the chloro compound XVII. Its substitution reactions with 1-methylpiperazine, 1-(2-hydroxyethyl)piperazine and 1-phenylpiperazine resulted in the piperazines VIb-VIIIb. Acylations of the amine IIIb with acetic anhydride and homoveratroyl chloride gave the amides Xb and XIb which, together with the formamide IXb, were subjected to the Bischler-Napieralski reaction. 3,4-Dihydroisoquinolines XXII-XXIV were obtained and reduced to the 1,2,3,4-tetrahydroisoquinolines XXVb-XXVIIb. Treatment of XXVIIb with formaldehyde afforded the berbine derivative XXVIII. Demethylation of the amine IIIb with hydrobromic acid resulted in the title compound IIIa. Similar demethylations of the dimethoxyamines IVb-VIIIb, XXVb and XXVIb led to the dihydroxyamines IVa-VIIIa, XXVa and XXVIa which are dopamine derivatives. Reaction of Va with benzoyl chloride gave the dibenzoate XXX. The CNS activities of the compounds prepared are of a low degree. Several of them (IIIa-VIa, IIIb-Vb, XXVb) show in higher doses signs of central stimulant action but only for compound IVa an antireserpine effect was proven. The expected anticataleptic activity was found only in a low degree with compound VIIIa; on the contrary, compounds IIIa and XXVa are procataleptogenic. Some compounds (IIIa, IXb, XXVIa, XXVIII) potentiated thiopental. In single cases local anaesthetic, spasmolytic, hypotensive, hypertensive, hypoglycaemic, diuretic and antiarrhythmic effects were observed.