E. V. Gromachevskaya

Studies of 4H-3,1-benzoxazines: 13. Bromination of 1,2-dihydro-4H-3,1-benzoxazines

Bromination of 2,4-substituted 1,2-dihydro-4H-benzoxazines with bromine in acetic acid was conducted. It was shown that either the corresponding 6,8-dibromo-1,2-hydrobenzoxazines or the products of their dehydrogenation — 6,8-dibromobenzoxazines, are primarily formed as a function of the structure of the dihydrobenzoxazine and the concentration of bromine in the reaction mixture. The structure of 6,8-dibromo-2-(5-nitrofuryl-2)-4, 4-diphenyl-1,2-dihydro-4H-3,1-benzoxazine was investigated by XSA. A stacking interaction between the nitrofuran fragment of one molecule and the condensed benzene ring of the other was detected in the crystal.

Substituted 2-Formylbenzoic Acids in the Synthesis of 11H-Isoindolo[2,1-a]Benzimidazol-11-Ones, 5H-Isoindolo[2,1-a][3,1]Benzoxazine-5,11(6aH)-Diones, and 6,6a-Dihydroisoindolo-[2,1-a]Quinazoline-5,11-Diones

Optimal conditions were developed for the synthesis of 11H-isoindolo[2,1-a]benzimidazol-11-one, 5H-isoindolo[2,1-a][3,1]benzoxazine-5,11(6aH)-dione, and 6,6a-dihydroisoindolo[2,1-a]quinazoline-5,11-dione derivatives in the reaction of substituted 2-formylbenzoic acids with o-phenylenediamine, anthranilic acid, and anthranilamide, respectively. The bifolded structure of 6,6a-dihydroisoindolo-[1,2-a]quinazoline-5,11-dione was verified and investigated.

Synthesis of 3,4-Dihydroquinazolines in the Reaction of o-Aminophenyldiphenylcarbinol with Nitriles

The reaction of o-aminophenyldiphenylcarbinol with nitriles of various structure in the presence of perchloric acid has been investigated. Optimal conditions have been developed for the synthesis of 3,4-dihydroquinazolinium perchlorates, from which the corresponding 3,4-dihydroquinazolines are obtained by treatment with bases. Certain compounds with an active methylene group bound directly to the heterocycle are able to exist in tautomeric forms with migration of the multiple bond into an exocyclic position.

Studies on quinazoline chemistry. 5.* Synthesis of 3,4-dihydroquinazolines with functional substituents at C-2 atom and their alkylation reactions

Syntheses are reported for a new series of 2-substituted 4,4-diphenyl-3,4-dihydroquinazolines by the reaction of o-aminophenyldiphenylcarbinol (APC) with various nitriles. The reaction of APC with substituted 5-bromo-3-cyano-2(1H)-pyridones leads to the formation of derivatives of two products: 3,4-dihydroquinazolines and 4H-3,1-benzoxazines. The alkylation of 3,4-dihydroquinazolines using dimethyl sulfate proceeds through N,N-dimethylation. The structure of these products is a function of the nature of the substituent at C-2 atom of the heterocycle.

Studies on quinazoline chemistry. 4. Unexpected route of acylation of alkyl 2-(4,4-diphenyl-1,2,3,4-tetrahydro-2-quinazolinylidene)acetates. molecular structure of methyl 2-(4,4-diphenyl)-1,2,3,4-tetrahydro-2 -quinazolinylidene )-3-oxobutanoate

A study of the reaction of quinazoline derivatives with acid chlorides in the absence of acids has shown that alkyl 2-(4,4-diphenyl-1,2,3,4-tetrahydro-2-quinazolinylidene)acetates undergo C-acylation. The molecular structure of methyl 2-(4,4-diphenyl-1,2,3,4-tetrahydro-2-quinazolinylidene)-3-oxobutanoate has been investigated by X-ray analysis.

Studies of 4H-3,1-benzoxazines. 14. Structure and some properties of 2 -[2 -hydroxyphenyl (naphthyl)]-1,2-dihydro-4H-3,1-benzoxazines

It has been shown that the condensation of tertiary aminophenylcarbinols with 2-hydroxybenz(naphth)aldehydes gives the corresponding 1,2-dihydrobenzoxazines and their structural Schiff base isomers. The reaction of 2-[2-hydroxyphenyl(naphthyl)]-1,2-dihydro-4H-3,1-benzoxazines with aliphatic aldehydes gives substituted 3,1-benzoxazino[1,2-c][1,3]benz(naphth)oxazines.

Research on 4H-3,1-benzoxazines. 9. 2-Alkyl(aryl, furyl)-4H-3,1-benzoxazinium perchlorates and their transformations

A new method was developed for obtaining 4,4-diphenyl-4H-3,1-benzoxazinium Perchlorates by acylation of o-aminophenyldiphenylcarbinol with organic acids in the presence of perchloric acid. Weak CH acidity of the exocyclic methyl group of the corresponding perchlorate was observed.

Research on 4H-3,1-benzoxazines. 8. Synthesis and properties of 4H-3,1-benzoxazinium chlorides

A mechanism for the acylation of substituted o-aminophenylcarbinols with carboxylic acid chlorides and the formation of 2-alkyl(aryl, furyl)-4H-3,1-benzoxaziniun chlorides is proposed. The nitration and introduction of a sulfur atom into the heterocyclic ring of the 4H-3,1-benzoxazinium salts were investigated.

4H-3,1-benzoxazines. 2. Synthesis of 2,4-substituted 1,2-dihydro-4H-3,1-benzoxazines

The reactions of o-aminophenylcarbinols with carbonyl compounds have been studied. Optimum conditions have been developed for the synthesis of 2-(5-X-2-furyl)-1,2-dihydro-4H-3,1-benzoxazines. It was found that 2,2-disubstituted 1,2-dihydro-4H-3,1-benzoxazines are unstable and are converted upon heating in the presence of acylating agents to 4H-3,1-benzoxazines.

New Reactions of (2-Aminophenyl)diphenylmethanol with Carbonyl Compounds

Reactions of (2-aminophenyl)diphenylmethanol with ketones (dimedone, camphor, and 3-bromocamphor) in acetic acid result in the formation of arylimines of camphore and 3-bromocamphore, substituted tetrahydroacridin-1(2H)-one and 2-methyl-4,4-diphenylbenzoxazine.