Online article for Non-subscribers

Pay per view

Heterocycles has a pay-per-view service for Non-subscribers.
You will be able to directly purchase the full text article through PayPal.
Your purchased Paper can be downloaded after the payment is completed.
An e-mail will be sent the URL to download the paper.
If you have any questions, please contact: purchase@heterocycles.com

Price: ¥ 4,320 (Yen only)
Period: This Article can be accessed for 7 days.

Short Paper | Regular issue | Vol 89, No. 8, 2014, pp.1892-1904
Published online, 16th June, 2014
DOI: 10.3987/COM-14-13026
Multicomponent and Regioselective Synthesis of Dihydropyrazolo[1,5-a]pyrimidines from Aromatic Aldehydes, Meldrum’s Acid, and Aminopyrazole CAN508

Lukáš Jedinák, Vladimír Kryštof, Zdeněk Trávníček, and Petr Cankař*

*Department of Organic Chemistry, Palacký University, 17. listopadu 12, 77146 Olomouc, Czech Republic

Abstract

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.