Līpiņš DD, Jeminejs A, Ušacka U, Mishnev A, Turks M, Novosjolova I. Regioselective quinazoline C2 modifications through the azide-tetrazole tautomeric equilibrium.
Beilstein J Org Chem 2024;
20:675-683. [PMID:
38590535 PMCID:
PMC10999978 DOI:
10.3762/bjoc.20.61]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Accepted: 03/18/2024] [Indexed: 04/10/2024] Open
Abstract
2-Chloro-4-sulfonylquinazolines undergo functional group swap when treated with an azide nucleophile: 1) the azide replaces the sulfonyl group at the C4 position; 2) the intrinsic azide-tetrazole tautomeric equilibrium directs the nucleofugal sulfinate from the first step to replace chloride at the C2 position. This transformation is effective with quinazolines bearing electron-rich substituents. Therefore, the title transformations are demonstrated on the 6,7-dimethoxyquinazoline core, which is present in pharmaceutically active substances. The methodology application is showcased by transforming the obtained 4-azido-6,7-dimethoxy-2-sulfonylquinazolines into the α1-adrenoceptor blockers terazosin and prazosin by further C2-selective SNAr reaction and azide reduction.
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