Díaz JE, Ranieri S, Gruber N, Orelli LR. Syntheses of 3,4- and 1,4-dihydroquinazolines from 2-aminobenzylamine.
Beilstein J Org Chem 2017;
13:1470-1477. [PMID:
28845190 PMCID:
PMC5550820 DOI:
10.3762/bjoc.13.145]
[Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Accepted: 06/30/2017] [Indexed: 11/23/2022] Open
Abstract
A straightforward strategy for the synthesis of dihydroquinazolines is presented, which allows for the preparation of 3,4- and 1,4-dihydroquinazolines with different substitution patterns from 2-aminobenzylamine (2-ABA) as common precursor. The required functionalization of both amino groups present in 2-ABA was achieved by different routes involving selective N-acylation and cesium carbonate-mediated N-alkylation reactions, avoiding protection/deprotection steps. The heterocycles were efficiently synthesized in short reaction times by microwave-assisted ring closure of the corresponding aminoamides promoted by ethyl polyphosphate (PPE).
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