10441-26-6Relevant articles and documents
PROCESS AND PRODUCT
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Page 7; 22; scheme, (2010/02/09)
A process of preparing perindopril of formula (I), or a pharmaceutically acceptable salt thereof which process comprises protecting a compound of formula (II) where R denotes a hydrogen atom, in the presence of benzene sulphonic acid as a catalyst, to obtain the benzene sulphonic acid salt of an ester of formula (III) where Rl is a carboxyl protecting group and reacting said ester of formula (III) with N-[(S)-1-carbethoxybutyl]-(S)-alanine to obtain a compound of formula (IV) where Rl is as defined above; and deprotecting a compound of formula (IV) to yield perindopril of formula (I), or a pharmaceutically acceptable salt thereof. There is also provided by the present invention the benzene sulphonic acid salt of an ester of formula (III), and perindopril or a pharmaceutically acceptable salt thereof prepared by the above process.
1,3-Dipolar Cycloaddition Reactions. Regioselective Synthesis of Heterocycles and Theoretical Studies
Pierini, Adriana B.,Cardozo, Mario G.,Montiel, Aida A.,Albonico, Sem M.,Pizzorno, Maria T.
, p. 1003 - 1008 (2007/10/02)
We report a 1,3-dipolar cycloaddition reaction between a oxazolium 5-oxide derivative with chloroacrylonitrile or ethyl propiolate as dipolarophiles, in order to obtain substituted pyrrolizidines.Experimentally we found that the reaction is regiospecific with chloroacrylonitrile and regioselective with ethyl propiolate.The secondary attractive orbital interactions from the Frontier Molecular Orbital Theory, the differences in stability of the possible biradical intermediaries postulated for the reaction and some hindrance effects, explain the regioselectivity observed experimentally.
