Facile Synthesis of 3-Nitro-2-substituted Thiophenes
作者:Cornelius J. O’ Connor、Mark D. Roydhouse、Anna M. Przybył、Michael D. Wall、J. Mike Southern
DOI:10.1021/jo902656y
日期:2010.4.16
A new approach to 3-nitro-2-substituted thiophenes has been developed. Exposure of commercially available 1,4-dithane-2,5-diol to nitroalkenes in the presence of 20% triethylamine results in a tandem Michael intramolecular Henry reaction to form the corresponding tetrahydrothiophene. Subsequent microwave irradiation on acidic alumina in the presence of chloranil effects the solvent free dehydration and aromatization to form 3-nitro-2-substituted thiophenes cleanly and rapidly. A simple workup procedure removes the requirement for purification by chromatography in most cases.
Iwanowa, Zhurnal Obshchei Khimii, 1958, vol. 28, p. 1232,1233, 1235; engl.Ausg. S. 1288, 1290, 1291