V. A. Zagorevskii

Synthesis of 2,3,4,5-tetrahydro-1,5-benzox (and thi)azepines and their utilization for the preparation of condensed indoles

A preparative method is proposed for the synthesis of 2,3,4,5-tetrahydro-1,5-benzothiazepine by reductive ring expansion of 4-chromanone and 4-thiochromanone oximes. These compounds were converted to the corresponding N-amino derivatives, which, like arylhydrazines in the Fischer reaction, give new condensed indole systems. The reduction of the oxime (and its tosylate) of 5-oxo-2,3,4,5-tetrahydro-1-benzoxepine was investigated.

Investigations of pyrans and related compounds

The action of phosphorus oxychloride in DMFA on 4-hydroxy-3-nitrocoumarin has given 4-chloro-3-nitrocoumarin, by the reaction of which with amines and ammonia 4-amino-3-nitrocoumarins have been synthesized; some of their physicochemical properties have been studied.

Synthesis and pharmacological activity of benzothiazine derivatives

The pharmacological activity of the synthesized compounds was studied in mice with the help of methods used for the initial evaluation of antidepressant, neuroleptic, and tranquilizing action, it was established that the studied compounds were capable of strengthening the action of pharmacological substances, stimulating dopaminergic and serotoninergic mediated processes in the central nervous system~ The spectrum of activity of these compounds showed several features resembling those of antidepressants.

Synthesis and pharmacological activity of 4H-[1]-benzopyrano[3,4-d]imidazol-4-ones

pendent stretching vibrations of C=C and C=N bonds). The stretching vibrations of the NH group in the spectrum of compound IIa appear at 3400 and 3230 cm-i; the weak band at 3100 cm -~ present in the spectra of imidazoles IIa-j corresponds to the vibrations of the CH bonds. In the PMR spectrum of compound IIf there are Unresolved groups of signals at 0.8-2.2 ppm (7H, CHsCH2CH2--), a triplet signal (J = 7.5 Hz) at 4.5 ppm (2H; --CH2N--), and sevemal signals at 7-8.2 ppm (5H; C~H~ and 2-H). In the mass spectra of these compounds, there is a molecular ion peak that, in general, has maximum intensity.

Studies of pyrans and related compounds

The fine structures of the products of the cleavage of the heterorings of chromones and 4-pyrones by ammonia and primary and secondary amines, i.e., 2-β-aminoacrylylphenols (I) and di(β-aminovinyl) ketones (II), were studied by means of IR and PMR spectra, and it was established that I and II, which contain amino groups with a hydrogen atom attached to the nitrogen, exist in the cis form with double intramolecular (chelate) bonding between one carbonyl and two proton-containing groups.

Ring closure of some O-aryl ethers of ketoximes to benzofurans

The action of alcohol solutions of hydrogen chloride on aryl ethers of the oximes of N-substituted 4-piperidones (Ia-c) yielded rearrangement products — 3-(2-hydroxyaryl)-4-piperidones (IIa, b) and (or) 4a-aikoxy-l,2,3,4,4a,9b-hexahydrobenzofuro[3,2-c]pyridines (IIIa-c), which, under certain conditions, are readily converted to 1,2,3,4-tetrahydrobenzofuro[3,2-c]pyridines (IVa, b). Ketones of the II type are ketalized to dihydrobenzofurans III by alcohol solutions of hydrogen chloride.

Research on pyranes, their analogs, and related compounds

Reaction of sodium azide with chromone-2-carbonyl chloride or the action of nitrous acid on the hydrazide of chromone-2-carboxylic acid, existing in the cyclic form 3′-oxopyrazolidino[4′,5′∶2, 3]-chroman-4-one, gives the azide of chromone-2-carboxylic acid, the Curtius rearrangement of which is used to synthesize a number of 2-acylaminochromones.

A new synthesis of benzofuro[3,2-c]pyridines

The condensation of O-phenylhydroxylamine with piperidin-4-one and 3-methylpiperidin-4-one has given 1,2,3,4-tetrahydrobenzofuro[3,2-c]pyridine and 4-methyl-1,2,3,4-tetrahydro-benzofuro [3,2-c]pyridine, and these have been dehydrogenated to the corresponding heteroaromatic system of benzofuro[3,2-c]pyridine.

Synthesis of certain 2-acyl-4-methylphenols

ConclusionOn the basis of the Fris rearrangement of complex esters of n-cresol, 2-acyl-4-methylphenols (I–III) were synthesized and used for certain subsequent conversions.

Tautomerism of 1-phenyl-3-methyl-4-benzyl-5-pyrazolone

The tautomerism of 1-phenyl-3-methyl-4-benzyl-5-pyrazolone —a side product in the reaction of acetoacetic ester with benzaldehyde phenylhydrazone — was studied by IR and PMR spectroscopy, and its thermodynamic characteristics were determined.