86688-94-0Relevant academic research and scientific papers
Regioselective Synthesis of Acylpyrroles
Kakushima, Masatoshi,Hamel, Pierre,Frenette, Richard,Rokach, Joshua
, p. 3214 - 3219 (2007/10/02)
The regioselective synthesis of several pyrrole derivatives is described.AlCl3-catalyzed acylation reactions of 1-(phenylsulfonyl)pyrrole (1) give 3-acyl derivatives, whereas the corresponding BF3*OEt2-catalyzed reactions give 2-acyl derivatives predominantly.Mild alkaline hydrolysis gives the corresponding acyl-1H-pyrroles in excellent yields.AlCl3-catalyzed reactions of 1 with 1,1-dichloromethyl methyl ether and oxalyl chloride give 1-(phenylsulfonyl)-2-formylpyrrole (6) and 1-(phenylsulfonyl)-2-(chlorocarbonyl)pyrrole (7), respectively. 3-Pyrrolylacetic acid (10) was prepared by thallium(III) nitrate promoted rearrangement of 1-(phenylsulfonyl)-3-acetylpyrrole (2a).Trifluoroacetic anhydride catalyzed cyclization of 4-butyric acid (14) gives 1-(phenylsulfonyl)-7-oxo-4,5,6,7-tetrahydroindole (17).Attempts to cyclize 14 at the 4-position have been unsuccessful.
