Mechanism of recyclization of furans to thiophenes and selenophenes under acid catalysis. 1. Kinetic studies of the reaction of 2,5-dialkylfurans with hydrogen sulfide in the presence of hydrochloric acid
The transformation of 2,5-dialkylfurans to thiophenes by reaction with hydrogen sulfide in the presence of hydrochloric acid was studied. The reaction was found to be first order with respect to the furan; the rate of consumption of the furan did not change with increasing length of one of the alkyl substituents. Recyclization in the presence of acid proceeds in two independent directions: through the formation of an intermediate dicarbonyl compound, and by direct conversion of the furan to a thiophene. Kinetic data showed that the reaction occurs mainly by the second route.
KeywordsHydrogen Sulfide Organic Chemistry Catalysis Hydrochloric Acid
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- 1.V. G. Kharchenko, I. A. Markushina, and T. I. Gubina, Dokl. Akad. Nauk SSSR, 255, 1144 (1980).Google Scholar
- 2.V. G. Kharchenko, T. I. Gubina, and I. A. Markushina, Zh. Org. Khim., 18, Issue 2, 394 (1982).Google Scholar
- 3.V. G. Kharchenko, I. A. Markushina, and S. P. Voronin, Khim. Geterotsikl. Soedin., No. 2, 219 (1983).Google Scholar
- 4.V. G. Kharchenko, S. P. Voronin, T. I. Gubina, I. A. Markushina, and A. F. Oleinik, Khim. Geterotsikl. Soedin., No. 12, 1606 (1984).Google Scholar
- 5.E. I. Stamhuis, W. Drenth, and H. Van den Berg, Rec. Trav. Chim., 83, 167 (1964).Google Scholar
- 6.P. Salomaa, A. Kankaanpera, and M. Lagunen, Acta Chem. Scand., 20, 1790 (1966).Google Scholar
- 7.K. Unterferth and K. Schwetlick, J. Prakt. Chem., 312, 882 (1970).Google Scholar