The regioselectivity of the formation of 2-pyrazolylthiazoles and their precursors from the reaction of 2-hydrazinothiazoles with 4,4,4-trifluoro-1-hetaryl-1,3-butanediones / Denisova AB,Sosnovskikh VY,Dehaen W,Toppet S,Van Meervelt L,Bakulev VA // JOURNAL OF FLUORINE CHEMISTRY. - 2002. - V. 115, l. 2. - P. 183-192.

ISSN/EISSN:

0022-1139 / нет данных

Type:

Article

Abstract:

Reaction of 2-hydrazinothiazoles 1 with 1-thienyl- and 1-furyl-1,3-butanediones 2a,b in methanol in the presence of hydrochloric acid mainly leads to a mixture of pyrazoles 3 and pyrazolines 4 or pyrazoles 3 and 5 in strong acidic conditions. Isomeric hydrazones 6 and pyrazolines 4 were formed and isolated in these reactions in the absence of hydrochloric acid. It has been shown that the regioselectivity in the reaction of diketones 2 with hydrazine 1 is governed by both the concentration of acid and the nature of substituents in the 1,3-diketones 2. Cyclization of hydrazones 6 is shown to occur under milder conditions than dehydration for pyrazolines 4. The new heterocyclic compounds were prepared and fully characterized by NMR spectra and by X-ray analysis for 3c. (C) 2002 Elsevier Science B.V. All rights reserved.

Author keywords:

pyrazolylthiazoles; regioselectlvity; 2-hydrazinothiazoles; 1,3-diketones; H-1; F-19; C-13 NMR 1,3-DIKETONES

DOI:

10.1016/S0022-1139(02)00060-X

Web of Science ID:

ISI:000176607900014

Соавторы в МНС:

Другие поля

Поле	Значение
Month	JUN 28
Publisher	ELSEVIER SCIENCE SA
Address	PO BOX 564, 1001 LAUSANNE, SWITZERLAND
Language	English
Article-Number	PII S0022-1139(02)00060-X
Keywords-Plus	1,3-DIKETONES
Research-Areas	Chemistry
Web-of-Science-Categories	Chemistry, Inorganic \& Nuclear; Chemistry, Organic
Number-of-Cited-References	13
Usage-Count-Last-180-days	1
Usage-Count-Since-2013	2
Journal-ISO	J. Fluor. Chem.
Doc-Delivery-Number	569NF