Benzothiazine and benzothiazepine derivatives: synthesis and preliminary biological evaluation

Several tricyclic benzothiazines and benzothiazepines have been synthesized by different intramolecular cyclization reactions. Their functionalization led to biologically active compounds. Some stereochemical aspects as well as biological responses have been outlined.

Research on compounds with psychotropic activity. IX--Synthesis of 6-p-methoxyphenylpyrrolo[2,1-d][1,5]benzothiazepines and evaluation of their affinities for BDZ and GABA receptor subtypes

6-p-Methoxyphenylpyrrolo[2,1-d][1,5]benzothiazepin-7(6H)-one (IV), cis-7-acetoxy-6,7-dihydro-6-p-methoxyphenylpyrrolo[2,1-d] [1,5]benzothiazepine (V) and some significant 7-acyloxy-6-p-methoxyphenylpyrrolo[2,1-d][1,5]benzothiazepines (VI a-g) were synthesized and tested in vitro for inhibition of the specific binding of 3H-Flunitrazepam, 3H-PK 11195, 3H-Muscimol and 3H-(-)Baclofen to central and peripheral benzodiazepine, GABA-A and GABA-B receptors, respectively. The compounds (IV), VI a) and (VI c) were active on the peripheral benzodiazepine receptor; in particular (VI a) and (VI c) were very active. The compound (VI g) showed an affinity, even though scanty, for the central benzodiazepine receptor.

[Compounds with psychotropic activity. VIII. Synthesis and sedative activity of various 9-substituted derivatives of 5-phenylpyrrolo[2,1-d][1,5] benzothiazepine and cis-4,5-dihydro-4-hydroxy-5-phenylpyrrolo[2,1-d][1,5]benzothiazepine]

Syntheses of 9-chloro-, 9-trifluoromethyl- and 9-methoxy-5- phenylpyrrolo [2,1-d] [1,5] benzothiazepine [II a-c] and of cis-9-chloro- and cis-9-trifluoromethyl-4,5-dihydro-4-hydroxy-5- phenylpyrrolo [2,1-d] [1,5] benzothiazepine with the respective acetyl derivatives (III a-d), according to previously restated routes, are described. The sedative activity was tested against the anti-amphetamine activity in the rat. The 1-[5-trifluoromethyl-2-(alpha- hydroxycarbonylbenzyl ) thiophenyl + ++]-pyrrole ( NF34 ) and the pyrrolo [2,1-d] [1,5] benzothiazepine -5-carboxamide ( NF44 ) showed sedative activity similar to that of diazepam.

[Research on a compound with psychotropic activity. V - a new derivative of pyrrolo[2,1-d][1,5]benzothiazepin-6,6-dioxide: synthesis and sedative activity]

The following compounds have been synthesized according to a previously tested route, of the 9-chloro-, 9-trifluoromethyl- and 9-methoxy-5-phenylpyrrolo[2,1-d][1,5]benzothiazepin-6,6-dioxide (II a-c), 9-chloro- and 9-trifluoromethyl-5-p-nitrophenylpyrrolo[2,1-d][1,5]benzothiazepin-6,6-dioxide (II d, e), 5-(4-pyridyl)pyrrolo[2,1-d][1,5]benzothiazepin-6,6-dioxide (III) and 5-(3-pyridyl)pyrrolo[2,1-d][1,5]benzothiazepin-6,6-dioxide (IVa) with the 9-chloro- and 9-trifluoromethyl- derivatives (IV b, c) are reported. The sedative action in the rat was tested against the motor activity induced by amphetamine. The 9-chloro-5(3-pyridyl)pyrrolo[2,1-d][1,5]benzothiazepin-6,6-dioxide was particularly active and showed sedative action superior to that of diazepam. Marked sedative activity was observed with 9-methoxy-5-phenylpyrrolo[2,1-d][1,5]benzothiazepin-6,6-dioxide (NF19) and 9-chloro-5-p-nitrophenylpyrrolo[2,1-d][1,5]benzothiazepin-6,6-dioxide (NF20).

[Studies on substances with antiblastic activity. IX. Anthramycin and analogs. IX. Synthesis of 7-methoxy-8-hydroxy-10,11-dihydro-5H-pyrrolo[2,1-c] [1,4] benzodiazepine and other compounds related to oxotomaymycin]

The synthesis of some pyrrolobenzodiazepine derivatives related to oxotomaymycin, an antibiotic recovered together with tomaymycin from fermentation broths of Streptomyces achromogenes var. tomaymycetics, is described. Reaction between 2-nitro-4-benzyloxy-5-methoxybenzylbromide and pyrrole-2-carboxyaldehyde afforded 1-(2-nitro-4-benzyloxy-5-methoxybenzyl)pyrrole-2-carboxyaldehyde. Catalytic reduction of this compound with hydrogen in the presence of Pd/C gave 10,11-dihydro-8-hydroxy-7-methoxy-5H-pyrrolo[2.1-c] [1,4]benzodiazepine. Amides obtained from condensation between 2-nitro-4-benzyloxy-5-methoxybenzoic acid chloride and proline or hydroxyproline were reduced catalytically to 2,3-dihydro-8-hydroxy-7-methoxy-1H-pyrrolo [2,1-c] [1,4]benzodiazepine-5,11 (10H, 11aH)-dione and its 2-hydroxyderivative respectively. The synthesis of 10,11-dihydro-8-hydroxy-9-methoxy-5-pyrrolo [2,1-c] [1,4]benzodiazepine is also reported.

[Research on nitrogen heterocyclic compounds. XI. - New synthesis of 3H-benz(e)indole and its derivatives]

Glutaconic esters bearing a 2-naphthylamino moiety and a carbethoxy group at the 4-position underwent thermal decomposition to give 1-carbethoxy-3H-benz[e]indole derivatives. Alkaline hydrolysis of 1-carbethoxy-3H-benz[e]indoles gave the corresponding 3H-benz[e]indoles by loss of the carboxylic group. By this method were synthesized the known 3H-benz[e5indole and the 7-methoxy-3H-benz[e]indole. Glutaconic esters used in this procedure were prepared by condensation of ethyl propiolate with the appropriate 2-naphthylaminomalonate ethyl ester in the presence of a catalytic amount of sodium ethylate.

[Research on substances with psychotropic activity. IV. Synthesis of 2,3-diphenyl-4-methyl-4H-1,4-benzothiazin-1,1-dioxide by thermal cyclization of N-(2-desylsolfonylphenyl) glycine]

Treatment of the ethyl ester of N-benzoyl-N-(2-benzylsolfonylphenyl)glycine with potassium in benzene gave, by rearrangement, N-(2-desylsolfonylphenyl)glycine, which via thermal intramolecular cyclization and simultaneous decarboxylation gave 2,3-diphenyl-4-methyl-4H-1,4-benzothiazin-1,1-dioxide. The structure of the latter compound was confirmed chemically by oxidising the known 2,3-diphenyl-4-methyl-4H-1,4-benzothiazine with hydrogen peroxide in formic acid and by I;R. and N.M,R; spectral data.

[Research on nitrogen heterocyclic compounds. IX. Synthesis of 5-hydroxy-2,4-dicarbethoxypyrroles]

Reaction between diethyl ethoxymethylenemalonate and N-substituted diethylaminomalonates in the presence of sodium ethoxide gives 5-hydroxy-2,4-dicarbethoxypyrroles. By treating these compounds with acetic anhydride we shall get the corresponding 5-acethoxy-2,4-dicarbethoxypyrroles and, by catalytic reduction, the corresponding 2,4-dicarbethoxy-5-pyrrolidinones, which in turn are hydrolyzed to the well known corresponding pyroglutamic acids. The I.R. and N.M.R. spectral data are in agreement with the proposed structures.