Phosphorus oxychloride → 1-(5-(4-chlorophenyl)-1,4-dimethyl-1H-pyrrol-2-yl)-2-cyclopropylethanone

Participants

Reaction Conditions

Reaction Steps

POCl3 (1.36 g, 0.82 ml, 8.88 mmol) was added to 2-cyclopropyl-N,N-dimethylacetamide (prepared according to the procedure described in Nils SchrOder et al., J. Am. Chem. Soc., 2012, 134, 8298-8301), 1.13 g (8.88 mmol) at 0° C. and under stirring and the reaction was continued at 0° C. for 15 min. The reaction mixture was allowed to warm up to room temperature, stirred for 20 min, and diluted with 1,2-dichloroethane (10 ml). 2-(4-chlorophenyl)-1,3-dimethyl-1H-pyrrole (prepared according to the procedure described in Kazuhiko Taguchi et. al., Tetrahedron Letters, 2005, 46, 4539-4542) (1.64 g, 8.0 mmol) was dissolved in 1,2-dichloroethane (20 ml) and was added to the reaction mixture at 0° C. The reaction mixture was heated to reflux temperature (95° C.) for 30 min. The progress of the reaction was monitored TLC. The reaction mixture was cooled to room temperature. Sodium acetate (4.01 g, 48.9 mmol) was dissolved in water (15 ml) and added to the reaction mixture. The reaction mixture was stirred at 100° C. for 1 hr. The progress of the reaction was monitored by TLC. The reaction mixture was cooled to room temperature, diluted with DCM (50 ml) and water (20 ml) was added to it. The organic layers were separated, dried over anhydrous sodium sulfate, filtered and concentrated to obtain a crude product. This crude product was purified by column chromatography using 5-10% ethyl acetate in hexanes as an eluent to obtain the title compound 3(0.77 g, 30.5%). MS: m/z 288 (M+1).

Provenance & Evidence