Download PDF
Synthesis 2003(15): 2353-2357  
DOI: 10.1055/s-2003-42407
PAPER
© Georg Thieme Verlag Stuttgart · New York

1,1,1-Trichloro-4,4-diethoxy-3-buten-2-one and its Trichloroacetylacetate Derivatives: Synthesis and Applications in Regiospecific Preparation of Azoles

Marcos A. P. Martins*, Claudio M. P. Pereira, Nilo E. K. Zimmermann, Sidnei Moura, Adilson P. Sinhorin, Wilson Cunico, Nilo Zanatta, Helio G. Bonacorso, Alex C. F. Flores
Núcleo de Química de Heterociclos (NUQUIMHE), Departamento de Química, Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS, Brazil
Fax: +55(55)2208031; e-Mail: mmartins@base.ufsm.br;
Further Information

Publication History

Received 15 May 2003
Publication Date:
29 September 2003 (online)

    Permissions and Reprints All articles of this category

Abstract

The synthesis of 1,1,1-trichloro-4,4-diethoxy-3-buten-2-one and three trichloroacetylacetate derivatives from the acylation reaction of respective trialkyl orthoacetates and orthopropionates with trichloroacetyl chloride in good yields, is reported. The title compounds were used for the regiospecific preparation of two isoxazoles and five pyrazoles in the cyclocondensation with hydroxylamine and hydrazines, respectively. The transformation of the trichloromethyl group under mild conditions into carboxylic groups is also described.

Key words

isoxazoles - pyrazoles - 4,4-diethoxy-3-buten-2-one - alkyl trichloroacetylacetates

22

4c: 1H NMR: δ = 1.36 (t, 3 H, CH3), 4.20 (q, 2 H, CH2), 3.25 (d, 1 H, J = 18 Hz, Hb), 3.70 (d, 1 H, J = 18 Hz, Ha). For 1H and 13C NMR data of 2a and 4d, see Table [1] .