MULTICOMPONENT AND REGIOSELECTIVE SYNTHESIS OF DIHYDROPYRAZOLO[1,5-a]PYRIMIDINES FROM AROMATIC ALDEHYDES, MELDRUM'S ACID AND AMINOPYRAZOLE CAN508

0433335 - ÚEB 2015 RIV JP eng J - Journal Article
Jedinák, L. - Kryštof, Vladimír - Trávníček, Z. - Cankař, P.
MULTICOMPONENT AND REGIOSELECTIVE SYNTHESIS OF DIHYDROPYRAZOLO[1,5-a]PYRIMIDINES FROM AROMATIC ALDEHYDES, MELDRUM'S ACID AND AMINOPYRAZOLE CAN508.
Heterocycles. Roč. 89, č. 8 (2014), s. 1892-1904. ISSN 0385-5414. E-ISSN 1881-0942
R&D Projects: GA MŠMT(CZ) LO1204
Institutional support: RVO:61389030
Keywords : Pyrazolo[1,5-a]pyrimidine * Cyclization * Multicomponent Reaction
Subject RIV: CC - Organic Chemistry
Impact factor: 1.079, year: 2014

A regioselective synthesis of dihydropyrazolo[1,5-a]pyrimidines is reported. The multicomponent reaction of readily available arylaldehydes, Meldrum's acid, and aminopyrazole CAN508 afforded fused pyrazolopyrimidines in high yields. The reaction proceeded regioselectively via initial Michael addition of the exocyclic amino group to arylidene Meldrum's acid intermediate followed by a ring closure at the endocyclic nitrogen of aminopyrazole. The regioselectivity of the reaction was determined by X-ray crystallography.
Permanent Link: http://hdl.handle.net/11104/0237601