A synthesis of 1-substituted 5-[2-(acylamino)ethyl]-1 H-pyrazole-4-carboxamides

A seven-step synthesis of 1-substituted 5-(2-acylaminoethyl)-1 H-pyrazole-4-carboxamides 20 as the pyrazole analogues of histamine was developed. The synthesis starts with a three-step preparation of N(1)-substituted methyl 5-(2- tert-butoxycarbonylaminoethyl)-1 H-pyrazole-4-carboxylates 7 from comm...

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Bibliographic Details
Published inTetrahedron Vol. 65; no. 34; pp. 7151 - 7162
Main Authors Kralj, David, Friedrich, Miha, Grošelj, Uroš, Kiraly-Potpara, Sonja, Meden, Anton, Wagger, Jernej, Dahmann, Georg, Stanovnik, Branko, Svete, Jurij
Format Journal Article
LanguageEnglish
Published Elsevier Ltd 2009
Subjects
Carboxamides
Enaminones
Histamine analogues
Hydrazines
Pyrazoles
Hydrazines
Pyrazoles
Enaminones
Histamine analogues
Carboxamides
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Summary:A seven-step synthesis of 1-substituted 5-(2-acylaminoethyl)-1 H-pyrazole-4-carboxamides 20 as the pyrazole analogues of histamine was developed. The synthesis starts with a three-step preparation of N(1)-substituted methyl 5-(2- tert-butoxycarbonylaminoethyl)-1 H-pyrazole-4-carboxylates 7 from commercially available Boc-β-alanine ( 1). Subsequent four-step transformation of the key-intermediates 7 into the final products 20 was performed following two complementary reaction sequences comprising acidolytic removal of the Boc group, hydrolysis of the COOMe group, amidations of the COOH group, and acylations of the NH 2 group. The structures of pyrazole derivatives were determined by spectroscopic methods and by X-ray diffraction. [Display omitted]
ISSN:0040-4020
1464-5416
DOI:10.1016/j.tet.2009.06.021