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A method for the synthesis of 2-R-2-(1-aryl-7,8-dimethoxy-5H-2,3-benzodiazepin-4-yl)acetic acid esters from 2-R-2-(1-aryl-7,8-dimethoxy-5H-2,3-benzodiazepin-4-ylsulfanyl)acetic acid esters through Eschenmoser reaction has been developed.

The base-mediated aminomethylation of 6-amino-4-aryl-2-thioxo-1,2-dihydropyridine-3,5-dicarbonitriles (I) provides access to pyridotriazine and tetrazocine derivatives in ratios depending strongly on the structure of the initial amine, the ratio of regents, and the reaction conditions.

A study has been made of thenitrationand bromination of 1-oxo-3,3,6-trimethyl-1,2,3,4-tetrahydrobenzo[bjfuro-, benzo[b]thieno-, and indolo[2,3-c]quinolines. It has been shown that the nitration is directed to the benzene ring (position 10). Bromination by molecular bromine takes place at the 6-CH3 group of the pyridine fragment and yields a mixture of the corresponding nwnobromomethyl and dibromomethyl derivatives, whereas a dimethylacetamide-bromine complex bronzinates the methylene group in position 2, forming the α-bromoketone. The Schmidt reaction of 1-oxo-3,3,6-trimetliyl-1,2,3,4-tetrahydrobenzo[b]furo-, benzol[b]thieno-, and indolo[2,3-c]quinolines have been investigated, as well as conversions of their oximes under conditions of the Beckmann rearrangement.

Treatment of N-phenyl-2-(1-R-indol-3-yl)succinimides with acetyl perchlorate leads to acylation of the benzene ring of the indole substituent.

The recyclization reactions of 4-cyanobenzo[c]pyrylium salts with ammonia, primary amines, and hydrazines have been studied. New derivatives of isoquinoline, benzo-2,3-diazepine, and pyrazolo-[ 5,4-c]isoquinoline have been obtained.

The examples reported for the recyclization of 3-acylaminobenzo[c]pyrilium salts are limited to their reactions with ammonia [1] and ortho-phenylenediamine [2], although the structure of these compounds would lead us to expect a great variety of transformations. In a study of 3-acylaminobenzo[c]pyrilium salts with nitrogen-containing nucleophiles, we assumed that the formation of 1,3-aminonaphthol derivatives would be possible in their reactions with amines as in the case of 5-alkyl-2-oxobenzo[c]pyrrolo[3,2-e]pyrilium perchlorates [3]. The structure of the products of the reactions of 3-acylamino-1-alkylbenzo[c]pyrilium salts (1) with benzylamine was found to depend on the length of the alkyl substituent at C(1) in the benzo[c]pyrilium cation. Heating 3-acetylamino-6,7-dimethoxy-1-methylbenzo[c]pyrilium perchlorate (1a) with two equivalents of benzylamine gives 3-acetylamino-1-benzylamino-6,7-dimethoxynaphthalene (2), whose structure and composition were indicated by IR and H NMR spectroscopy and elemental analysis. Under the same conditions, salt 1b is converted into the "normal" product, aminonaphthol 3. Recyclization with retention of the acetylamino group was quite unexpected since the reported reactions of 1-acylaminobenzo[c]pyrilium cations feature either loss of the acylamino group [1, 2] or participation of this group in intramolecular recyclization to give 3-hydroxyisoquinoline derivatives [4].