6704-19-4Relevant articles and documents
Dimerization of cyclopropanecarbonitrile mediated by Grignard reagents. Formation of highly substituted pyridines
Kolsaker, Per,Songe, Pal,Romming, Christian
, p. 1104 - 1111 (2007/10/03)
The reaction of cyclopropanecarbonitrile with ethylmagnesium bromide in diethyl ether followed by quenching with malononitrile gave the expected 2-cyano-3-cyclopropylpent-2-enonitrile (1a) in high yields. When the solvent was changed to tetrahydrofuran (THF) using ethylmagnesium chloride, low yields of 1a (12%) were obtained; the main products were two pentasubstituted pyridines, 2-amino-5-(2-chloroethyl)-3-cyano-6-cyclopropyl-4-ethylpyridine (2a, 70%) and 2-amino-3-cyano-5-(3,3-dicyanopropyl)-6-cyclopropyl-4-ethylpyridine (2c, 10%). In addition, their isomers, 2-amino-5-(2-chloroethyl)-3-cyano-4-cyclopropyl-6-ethylpyridine (3a, 7%) and 2-amino-3-cyano-5-(3,3-dicyanopropyl)-4-cyclopropyl-6-ethylpyridine (3c, 1%), were observed and identified by combined gas chromatography-mass spectrometry (GC-MS). When methyl-magnesium chloride was used (solvent THF), in addition to 1b and the isomers 2d, 2e, 3d and 3e, a tetrasubstituted pyridine, 2-amino-3-cyano-4,6-dicyclopropylpyridine (11), was formed. Similar reaction between cyclopropyl-magnesium bromide and cyclopropanecarbonitrile gave after hydrolysis about equal yields of dicyclopropyl ketone and a diketone, 1,1-di(cyclopropane-carbonyl)cyclopropane (8b). The structures of 2c and 2d were established by X-ray crystallography. Acta Chemica Scandinavica 1997.
