T. Nishiwaki
1967
Citations
0
Influential Citations
16
Citations
Journal
Tetrahedron
Abstract
Abstract The acetylation of 2-isovalerythiophene has been studied. Condensation of 2-acetylthiopene with ethyl acetate afforded 2-thenoylacetone, which reacted with acrylate ester (Michael condensation). Ureidomethylene-2-thenoylacetone was prepared and cyclized to the 5-thenoylpyrimidine. Mass spectra of 2-monoacyl-, 2,5-diacyl-, and 2-benzoylthiophenes were determined and their fragmentation patterns are discussed. α-Cleavage to the carbonyl group is the dominant feature affording the most prominent ion in most cases. The spectrum of 2-benzoylthiophene suggests that loss of mass units 28 with the phenyl migration from the molecular ion is a likely occurrence.