Potassium Carbonate → HCID 22902281, compound

Participants

Reaction Conditions

Reaction Steps

To a stirred mixture of 2,4-diacetyl-3,5-dimethylpyrrole (1.0 g), dichloromethane (35 cm3) and potassium carbonate (7.73 g) at 0°-5° C. was added a solution of sulphuryl chloride (0.79 g) in dichloromethane (15 cm3). The temperature of the mixture was maintained at 0.5° C. during the addition by external cooling and then the mixture was stirred at this temperature until adjudged complete by t.l.c. (ca 2 h). The mixture was then filtered and evaporated to give crude 2-chloromethyl-3,5-diacetyl-4-methylpyrrole. This material was dissolved in acetic acid (10 cm3), sodium acetate (1.83 g) added, and then more acetic acid (10 cm3) added. The mixture was stirred overnight at room temperature, evaporated in vacuo, and the residue stirred with ice-cold water for 2 h. A solid was collected by filtration and the filtrate extracted twice with ethyl acetate. The extracts were dried (MgSO4), evaporated and the residue combined with the solid above, to give the crude product. Chromatography on silica eluting with ethyl acetate-hexane (1:1) gave 0.075 g. of pure product as an off-white solid m.p. 112.5°-114.5° C.; m/z 238 (M+ +1, FAB), δH, CDCl3) 2.16 (3H, s, OCOCH3), 2.50 (3H, s, CH3), 2.53 (3H, s, CH3), 2.62 (3H, s, CH3), 5.38 (2H, s, OCH2).

Provenance & Evidence