A. I. Markosyan

Synthesis and Antineoplastic Properties of 3-Substituted 5,5-Dimethylbenzo[h]Quinazolin-4(3H)-Ones

Ethyl 2-cyano-3,3-dimethyl-4-phenylbutanoate was cyclized into 1-amino-3,3-dimethyl-3,4-dihydronaphthalene-2-ethylcarboxylate, condensation of which with isothiocyanates synthesized 3-substituted 5,5-dimethyl-2-thioxo-2,3,5,6-tetrahydrobenzo[h]quinazolin-4(1H)-ones. The antineoplastic properties of the synthesized compounds were studied.

Synthesis and psychotropic activity of 5-cyclohexyl-5-methyl-2-sulfanyl-3,4,5,6-tetrahydrobenzo[h]quinazolin-4-one

Ethyl 2-cyano-3-cyclohexyl-3-methyl-4-phenylbutanoate was synthesized from ethyl (2Z)-2-cyano-3cyclohexylbut-2-enoate using a Grignard reagent. It was shown that the reaction occurred exclusively at the ethylene bond. Because this cyanoester contained two asymmetric centers, PMR spectra showed two diastereoisomeric forms. These were cyclized in the presence of conc. H2SO4 into ethyl 4-amino-2-cyclohexyl-2-methyl-1,2-dihydronaphthalenecarboxylate, which was used to synthesize benzo[h]quinazolines, alkyl-substituted benzo[h]quinazolines, triazole, and tetrazole.

Some Transformations of 2-(Chloromethyl)-5,5-dimethyl-5,6-dihydrobenzo[h]quinazolin-4(3H)-one

The condensation of 1-amino-3,3-dimethyl-3,4-dihydronaphthalene-2-carbonitrile with chloroacetyl chloride afforded chloro-N-(2-cyano-3,3-dimethyl-3,4-dihydronaphthalen-1-yl)acetamide which underwent cyclization to 2-(chloromethyl)-5,5-dimethyl-5,6-dihydrobenzo[h]quinazolin-4(3H)-one. The latter reacted with various nucleophiles (alkali metal alkoxides, piperazine, 2-sulfanylethanol) to give 2-(alkoxymethyl)-, 2-(piperazin-1-ylmethyl)-, and 2-{[(2-hydroxyethyl)sulfanyl]methyl}-5,5-dimethyl-5,6-dihydrobenzo[h]quinazolin- 4(3H)-ones. The condensation of 2-(chloromethyl)benzo[h]quinazoline with 2-thioxo derivatives of quinazoline and benzo[h]quinazolines led to the formation of bis-quinazolines in which 5,5-dimethyl-5,6- dihydrobenzo[h]quinazolin-4(3H)-one fragment is linked to quinazoline or benzo[h]quinazoline system through a CH2S bridge.

Synthesis and Biological Activity of 2-Mercapto-7,10-Dimethyl-3 H -Spiro[Benzo[ H ]Quinazoline-5,1′-Cyclopentane]-4(6 H )-One from Ethyl 4′-Amino-5′,8′-Dimethyl-1′H-Spiro[Cyclopentane-1,2′-Naphthalene]-3′-Carboxylate

A synthetic method for 7,10-dimethyl-2-thioxo-2,3-dihydro-1H-spiro[benzo[h]quinazoline-5,1′-cyclopentane]- 4(6H)-one from ethyl 4′-amino-5′,8′-dimethyl-1′-H-spiro[cyclopentane-1,2′-naphthalene]-3′-carboxylate was developed. Reaction of the spirobenzo[h]quinazoline with various alkyl(benzyl) halides synthesized a novel series of spirobenzo[h]quinazolines containing methyl substituents on the benzene ring. The antidepressant, anticonvulsant, and antibacterial activities of the synthesized spirobenzo[h]quinazolines were investigated.

Synthesis and Antiproliferative Activity Evaluation of Aryl(Hetaryl)Cyclopentenone Analogs of Combretastatin A-4

A series of previously unreported di- and triaryl(hetaryl)cyclopentenone derivatives were prepared using a convenient synthetic method and screened preliminarily for antitumor activity in four human cell lines, i.e., T-cell leukemia (Jurkat), lung adenocarcinoma (A-549), colon cancer (HCT-116), and breast adenocarcinoma (MCF-7). The most cytotoxic of the tested compounds was 2-(3,4,5-trimethoxyphenyl)-3-(4-methoxyphenyl) cyclopent-2-en-1-one. However, it was inactive against lymphocytic leukemia P388 in mice despite its cytotoxicity in in vitro tests.

Synthesis, Conversions, and Anti-Monoamine-Oxidase and Anticonvulsant Activity of Ethyl 4′-Amino-5′,8′-Dimethyl-1′H-Spiro[Cyclohexane-1,2′-Naphthalene]-3′-Carboxylate

7,10-Dimethyl-2-thioxo-2,3-dihydro-1H-spiro[benzo[h]quinazoline-5,1′-cyclohexane]-4(6H)-one was synthesized from ethyl 4′-amino-5′,8′-dimethyl-1′H-spiro[cyclohexane-1,2′-naphthalene]-3′-carboxylate and reacted with various alkyl(benzyl)halides to afford a new series of benzo[h]quinazolines containing methyl substituents on the benzene ring. The anti-monoamine-oxidase and anticonvulsant activities of the benzo[h]quinazolines were studied.

Synthesis and Anti-Monoamine Oxidase and Antitumor Properties of Novel 3H-Spiro[Benzo[H] Quinazoline-5,1′-Cyclohexane]-4(6H)-One Derivatives

Amides that cyclized into 2-substituted 3H-spiro[benzo(h)quinazoline-5,1′-cyclohexane]-4(6H)-ones were prepared by reaction of 4′-amino-1′H-spiro[cyclohexane-1,2′-naphthalene]-3′-nitrile with carboxylic acid chlorides. Substitution of the benzoquinazolines by alcoholates, secondary amines, and thiolates was investigated. Thus,2-(3-chloropropyl)-3H-spiro[benzo[h]quinazoline-5,1′-cyclohexane]-4(6H)-one underwent intramolecular cyclization to form 10,11-dihydro-5H-spiro[benzo[h]pyrrolo[2,1-b]quinazoline-6,1′-cyclohexane]- 7(9H)-one whereas 2-chloromethyl-3H-spiro[benzo[h]quinazoline-5,1′-cyclohexane]-4(6H)-one formed substitution products. The influence of the synthesized compounds on brain monoamine oxidase activity was studied in vitro. It was found that the majority of the compounds inhibited deamination of 5-HT. The antitumor activity of the compounds was studied using two grafted murine tumor models, i.e., Ehrlich ascites carcinoma and sarcoma 180. Some of the investigated compounds suppressed tumor growth by 50 – 56%.

Synthesis and biological properties of 5,5-diethyl-2-substituted 4-oxo-3,4,5,6-tetrahydrobenzo[h]quinazoline derivatives

A series of new derivatives of benzo[h]quinazolines containing diethyl substituents at position 5 were synthesized. The alkylation of some 2-substituted 5,5-diethyl-4-oxo-3,4,5,6-tetrahydrobenzo[h]quinazolines with methyl iodide led to N-substituted products, while a similar reaction with ethyl iodide led to a mixture of N-substituted and O-substituted products. Some of the synthesized 5,5-diethyl-4-oxo-3,4,5,6-tetrahydrobenzo[h]quinazolines exhibit pronounced antiaminooxidase and weak antitumor properties.