Study of the cyclization of N-hydroxy- and N-methoxy-N-(2-oxoalkyl)amides

Study of the cyclization of N-hydroxy- and N-methoxy-N-(2-oxoalkyl)amides Full article

Journal

Chemical Papers
ISSN: 0366-6352 , E-ISSN: 1336-9075

Output data

Year: 2021, Volume: 75, Pages: 4517–4525 Pages count : DOI: 10.1007/s11696-021-01673-0

Tags

1,5-dihydro-2H-pyrrol-2-ones; 1,6-dihydropyridine-2,5-diones; Hydroxamic acid; Intramolecular cyclization; Oxidation reaction; X-ray structural analysis

Authors

Kulakov Ivan V. ¹ , Palamarchuk Irina V. ¹ , Nikolaenkova Elena B. ² , Tikhonov Alexsei Ya. ² , Gatilov Yuriy V. ² , Fisyuk Alexander S. ^3,4

Affiliations

1	Institute of Chemistry, Tyumen State University, 15a Perekopskaya St, Tyumen, 625003, Russian Federation
2	Siberian Branch of the Russian Academy of Science, N. N. Vorozhtsov Novosibirsk Institute of Organic Chemistry, 9 Akademika Lavrientieva Ave, Novosibirsk, 630090, Russian Federation
3	Omsk F.M, Dostoevsky State University, 55a Mira Ave, Omsk, 644077, Russian Federation
4	Laboratory of New Organic Materials, Omsk State Technical University, 11 Mira Ave, Omsk, 644050, Russian Federation

Abstract: Efficient methods for the preparation of 1-hydroxy-1,5-dihydro-2H-pyrrol-2-ones and 1-hydroxy-1,6-dihydropyridine-2,5-diones on the basis of N-hydroxy-N-(2-oxoalkyl)amides are reported. The reaction of N-hydroxy-N-(2-oxoalkyl)amides in the presence of 3 eq. of t-BuOK was found to lead to 1-hydroxy-1,5-dihydro-2H-pyrrol-2-ones. A decrease in the base content to 1.5 eq. or less leads to increase in 1-hydroxy-3-phenyl-1,6-dihydropyridine-2,5-dione content in the reaction products due to oxidation of the starting compounds by atmospheric oxygen and their subsequent transformation. Using the examples of chloroacetohydroxamic acids, we demonstrated the possibility of nucleophilic substitution and subsequent cyclization to 1-hydroxy-1,5-dihydro-2H-pyrrol-2-one derivatives. To study the possible mechanism of radical cyclization of N-hydroxy-N-(2-oxoalkyl) amides to 1,6-dihydropyridine-2,5-dione, the supposed reactive center (hydroxamic group) was blocked. It was shown that the protection of the N-hydroxy group by methylation of N-hydroxy-N-(2-methyl-3-oxobutan-2-yl)-2-phenylacetamide to N-methoxy-2-phenylacetamide in its further reaction with 0.5 eq. of t-BuOK results in the formation of intermediate 4-hydroxy-1-methoxy-3-phenylpyrrolidin-2-one. The desired 1-methoxy-1,5-dihydro-2H-pyrrol-2-one was obtained when using an excess of t-BuOK. Formation of N-methoxy-1,6-dihydropyridine-2,5-diones as a result of radical oxidative cyclization described earlier was not detected. Graphic Abstract: [Figure not available: see fulltext.]. © 2021, Institute of Chemistry, Slovak Academy of Sciences.

Kulakov I.V. , Palamarchuk I.V. , Nikolaenkova E.B. , Tikhonov A.Y. , Gatilov Y.V. , Fisyuk A.S.
Study of the cyclization of N-hydroxy- and N-methoxy-N-(2-oxoalkyl)amides
Chemical Papers. 2021. V.75. P.4517–4525. DOI: 10.1007/s11696-021-01673-0 WOS Scopus OpenAlex

Published online:

May 7, 2021

Web of science:	WOS:000647920100002
Scopus:	2-s2.0-85105508608
OpenAlex:	W3160786387

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