Diazafulvenones. Thermal isomerizations and eliminations in alkoxycarbonyl and anilinocarbonyl derivatives of imidazole

…, A Tommasetti, C Pedregal-Freire…

Index: Maquestiau, A.; Tommasetti, A.; Pedregal-Freire, C.; Elguero, J.; Flammang, R.; et al. Journal of Organic Chemistry, 1986 , vol. 51, # 3 p. 306 - 309

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Citation Number: 9

Abstract

4-Carbonyl-4H-imidazole (10) and 2-carbonyl-W-imidazole (1 1) are formed by flash vacuum pyrolysis of methyl 4-and 2-imidazolecarboxylates, respectively. 10 and 11 dimerize to diketopiperazines 14 and 16, respectively. The same products are also obtained from 4- and 2-(anilinocarbonyl) imidazoles, respectively. Methyl imidazole-1-carboxylate (4) on pyrolysis gives a ca. 1: l mixture of the same ketenes 10 and 11, which dimerizes to a 1: 21 ...