Parallel synthesis of 7-heteroaryl-pyrazolo[1,5-a]pyrimidine-3-carboxamides.
Mol Divers 2013;
17:731-43. [PMID:
23975596 DOI:
10.1007/s11030-013-9469-3]
[Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2013] [Accepted: 08/03/2013] [Indexed: 10/26/2022]
Abstract
A simple and practical four-step protocol for the parallel synthesis of 7-heteroaryl-pyrazolo[1,5-[Formula: see text]]pyrimidine-3-carboxamides was developed. The synthesis starts with transformation of commercially available 2-acetylpyridine and acetylpyrazine with [Formula: see text] [Formula: see text]-dimethylformamide dimethylacetal into the corresponding [Formula: see text]-3-(dimethylamino)-1-(heteroaryl)prop-2-en-1-ones followed by cyclisation with methyl 5-amino-1[Formula: see text]-pyrazole-4-carboxylate to give methyl 7-heteroarylpyrazolo[1,5-[Formula: see text]]pyrimidine-3-carboxylates. Hydrolysis of the ester group and subsequent amidation of the so formed carboxylic acids with 12 primary and secondary aliphatic amines furnished a library of 24 title compounds in good overall yields and purity.
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