Application of silica gel-supported polyphosphoric acid (PPA/SiO2) as a reusable solid acid catalyst to the synthesis of 3-benzoylisoxazoles and isoxazolines
摘要:
3-Benzoylisoxazoles were synthesized by the reaction of alkynes and benzoylnitromethane using silica gel-supported polyphosphoric acid (PPA/SiO2). This reaction provides a convenient, efficient, and reusable synthetic method of isoxazole derivatives. (C) 2011 Elsevier Ltd. All rights reserved.
A simple and direct method for the iron(III) nitrate-mediated synthesis of isoxazoles from alkynes has been developed; both self-coupling and cross-coupling products could be successfully prepared from alkynes. Meanwhile, for the cross-coupling and cyclizing of two different alkynes examined, the iron-mediated system shows a good chemoselectivity for the synthesis of corresponding isoxazoles. In our
gel-supported sodium hydrogen sulfate (NaHSO4/SiO2) or Amberlyst 15 as solid acid catalyst, and then the corresponding 3-acylisoxaszoles were obtained by reacting with alkynes via the 1,3-dipolar [3+2] cycloaddition. These heterogeneous catalysts are easily separable from the reaction mixture and reused. This synthetic method provides a facile, efficient, and reusable production of 3-acylisoxazoles.
Heterocyclic Derivatives as M3 Muscarinic Receptors
申请人:Avitabile Barbara Giuseppina
公开号:US20100056565A1
公开(公告)日:2010-03-04
This invention relates to M3 antagonists of formula (I) wherein R
2
, R
4
, R
5
, R
6
, W, V, A, D, X, t, u and v are as defined herein; pharmaceutical compositions containing them; methods for their preparation; and their use in the treatment of diseases where enhanced M3 receptor activation is implicated.