Announcement of the thesis defense of the Doctor of Philosophy (PhD) ​Allabergenova Sevara Mammadjanovna

Announcement of the thesis defense of the Doctor of Philosophy (PhD) Allabergenova Sevara Mammadjanovna

I. General information.

The topic of the dissertation, the cipher of the specialty (the name of the branch of science in which the academic degree is awarded): “synthesis and chemical transformations of sulfonamides in the series of bicyclic quinazolines”, 02.00.03 – organic chemistry.

The registration number of the thesis topic: В2024.4.PhD/K869.

Scientific supervisor: сandidate of Chemical Sciences, Senior Researcher Yakubov Ubaydullo Majitovich.

The name of the institution where the dissertation was performed: S. Yu. Yunusov Institute of the Chemistry of Plant Substances, Academy of Sciences of the Republic of Uzbekistan.

The defense will take place on  August 22, 2025 at 09:00 a.m.

The name of the institution where the Scientific council works, the number of the scientific council: S. Yu. Yunusov Institute of the Chemistry of Plant Substances, Academy of Sciences of the Republic of Uzbekistan, DSс.02/30.01.2020. К/Т. 104.01., kimyo fanlari doktori, professor

Official opponents: Doctor of Chemical Sciences, professor Yuldasheva Mukhabbat Razzokberdievna, PhD in chemical sciences, Associate professor Nasrullaev Azizbek Ozodovich.

Leading organization: Tashkent Pharmaceutical Institute.

II. The purpose of the study are quinazolin-4(3H)-one, 2-methylquinazolin-4(3H)-one, 2H(methyl, ethyl)-3-alkylquinazolin-4(3H)-ones, 2H(methyl, ethyl)-3-alkyl-4-oxo-3,4-dihydroquinazoline-6-sulfonamides synthesized on their basis and their new derivatives.

III. Scientific novelty of the research:

In the N³-alkylation reactions of 2H (alkyl) quinazolin-4(3H)-ones in the presence of alkaline catalysts, it was found that with an increase in the number of methylene groups of aliphatic radicals, the yield of alkyl products decreases in the order (4 (Me) > 5 (Et) > 6 (Pr) > 7 (Bu) > 8 (Pe) > 9 (Hx) > 10 (Hp)) and is explained by the effect of spatial factors;

for the first time, a One-pot synthesis method of 3-alkyl-, 2,3-dialkylquinazolones using chlorosulfonic acid and ammonia was successfully implemented, optimal methods for obtaining sulfonamides and a possible mechanism of the reactions were proposed;

it has been shown that sulfonylhydrazides containing a binucleophilic center with high synthetic potential can be formed by single-reactor reactions of 3-methyl (ethyl)-4-oxo-3,4-dihydroquinazolines, chlorosulfonic acid, and hydrazine hydrate;

it has been proven that nucleophilic substitution reactions of 3-butyl-4-oxo-3,4-dihydroquinazoline-6-sulfochloride with primary, secondary aromatic, and heterocyclic amines proceed easily with amino components of high basicity and yield new sulfonamides in high yields;

for the first time, the nucleophilic addition of 2,3-dialkylquinazolone sulfonamides to isomeric tolylisocyanates was carried out, and the formation of sulfonylureas was theoretically substantiated in the order p-CH₃< o-CH₃< m-CH₃, and a tentative mechanism of the reactions was proposed;

the optimal conditions for the targeted nucleophilic addition reactions of 2,3-dialkylquinazolone sulfonamides and p-methoxy(fluoro, chloro)phenylisocyanates, propylisocyanate, naphthylisocyanate (sulfonamide:isocyanate - 1:1.2, acetone, 56℃, 2.5-7 hours) were recommended;

it was found that the insecticidal activity increases depending on the type and location of the substituents in the substrate in the order 72 (11.6%) < 42 (21.6%) < 67 (45%) < 68 (58%) of the “aryl-hetaryl” hybrid molecules with a sulfonylurea fragment;

it has been found that quinazolones with arylidenesulfonyl fragments are formed as a result of the nucleophilic addition-elimination reaction of 2,3-dialkylquinazolone sulfonamides and substituted benzaldehydes in the presence of acid catalysts.

IV. Implementation of the research results.

Based on the scientific results obtained on the improved synthesis of 3-Alkyl- and 2,3-dialkylquinazolones, sulfochlorides, sulfonamides, sulfonylhydrazides based on them, the preparation of targeted nucleophilic substitution/addition products from them, and the determination of the structure and biological properties of the synthesized compounds:

X-ray diffraction results of 3-butyl-4-oxo-3,4-dihydroquinazoline-6-sulfonamide, 3-butyl-2-methyl-4-oxo-3,4-dihydroquinazoline-6-sulfonamide, 2-methyl-4-oxo-3,4-dihydroquinazolin-1-yl chloride are included into Cambridge Crystallographic Database (The Cambridge Structural Database, https://www.ccdc.cam, CCDC: 2190885, 2345709, 2416982). The results of including new compounds into the database made it possible to synthesize similar compounds and describe their structure;

the results of the synthesis and chemical transformation of sulfonamides, including bicyclic quinazolines, were used in the synthesis of quinazolin-4-one, 2-methylquinazolin-4-one, 2,3-dimethylquinazolin-4-one in the implementation of the fundamental project F-FA-2021-408: “Study of the patterns of introducing pharmacophoric fragments into a molecule based on modern cross-coupling and heterocyclization reactions” (2021-2024 (Certificate 4/1255-409 of the Academy of Sciences of the Republic of Uzbekistan dated Fevral 14, 2025). As a result, it was found that the Wilgerodt – Kindler reaction in the presence of synthesized 2-methylquinazolin-4-one and 2,3-dimethylquinazolin-4-one proceeded easily, and the synthesis of new thioamides was successfully carried out.

 

Print