4-Toluenesulfonyl chloride → 1-Tosylpyrrole

Participants

Reaction Conditions

Reaction Steps

Pyrrole (18 g, 0.27 mol) was added to a well-agitated suspension of NaOH (36 g, 0.9 mol. NaOH should be ground and stirred in dichloroethane for 30 min.) in 180 mL of dichloroethane. This mixture was then cooled to 0° C. and stirred for 10 min, following which a solution of 6 (57.3 g, 0.3 mol) in 150 mL of dichloroethane was added over a period of 30 min. Thirty minutes after the completion of addition, the reaction was allowed to come to room temperature and left stirring overnight. The reaction was quenched by pouring onto 600 mL of ice and water. The organic layer was separated, and the aqueous layer was extracted with dichloromethane (3×20 mL). The combined organic extract was washed with brine to neutrality and dried over Na2SO4. Removal of the solvent in vacuo gave 7 (45.3 g, 76%) as light grey solid. This solid was subsequently purified by passing a concentrated solution in dichloromethane through an alumina column (35.4 g). 1H NMR (CDCl3, δ/ppm), 7.75 (m, 2H), 7.29 (m, 2H), 7.15 (t, 2H), 6.28 (t, 2H).

Provenance & Evidence