Patent ID: 6552239
Filing Date: 2003-04-22
Classification: C07C,C07F

Abstract:
A process for the preparation of cyclopropaneacetylene comprising the steps of:(a) reacting a ketophosphonate compound of Formula I, with a diazo-transfer reagent, [(R*)2N]3P+N3Xâˆ’, wherein R* is C1-C5 alkyl and Xâˆ’ is halide, in the presence of a catalytic amount of a first non-nucleophilic base in an aprotic solvent to generate a reaction mixture containing ketodiazophosphonate compound of Formula II; wherein R1 and R2 substituents in Formulae I and II independently are: C1-C6 alkyl or aryl, wherein aryl is defined as phenyl or naphthyl which is unsubstituted or substituted with one or two substituents selected from the group consisting of: Cl, F, Br, I, (C1-C4)-alkyl, â€”Oâ€”(C1-C4)-alkyl, â€”NO2, â€”OH, CF3, (C1-C4)-alkoxy, S(O)xâ€”(C1-C4)-alkyl wherein x is 0, 1, or 2, â€”N(R)2, â€”COOR, and CON(R)2, wherein R is H, (C1-C6)-alkyl, phenyl, or (C1-C6)-alkylphenyl; and(b) reacting the reaction mixture containing the ketodiazophosphonate compound of Formula II with cyclopropanecarboxaldehyde using a second non-nucleophilic base and a protic solvent to yield the cyclopropaneacetylene.