Acetic Anhydride → 1-tosyl-3-acetylpyrrole

Participants

Reaction Steps

In a 1-liter three-neck flask fitted with a thermometer, a 50 cm3 funnel and a condenser with calcium chloride guard, 500 cm3 of dichloromethane and 80 g anhydrous aluminum chloride (600 mmoles) were added. 30 cm3 of acetic anhydride (320 mmoles) was dropwise added. The solution was stirred during 10 minutes. Then a 60 cm3 of dichloromethane solution containing 27 g of 1-tosyl pyrrole 1 (122 mmoles) was dropwise added. The stirring was maintained during 2 hours at room temperature, then the resulting solution was poured on 500 cm3 of water-ice mixture. After decantation, the aqueous layer was extracted with dichloromethane. The combine organic layer was washed with water, dried over magnesium sulfate and concentrated under reduced pressure to give 31 g of purple crystals 2 (M=263, yield: 96.7%). F (° C)=87 (purified by chromatography). NMR: (CDCl3) ppm 7.7 d J(Hz) 8 2H; 7.2 4H; 6.62 2H; 2.35 s 6H.

Provenance & Evidence