2,2,2-trichloro-1-(1H-pyrrol-2-yl)ethanone

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To trichloroacetyl chloride (48 mL; 0.43 mol) taken in anhydrous ether (150 mL) under nitrogen was added pyrrole (25 g, 0.37 mol) dissolved in anhydrous ether (500 mL) through a dropping funnel over a 2-hour period. The violet ether solution began to reflux during addition. Refluxing was continued for 1 h before the reaction was quenched with a solution of sodium carbonate (33 g, 0.31 mol) in water (200 mL). The layers were separated and the red organic layer was washed four times with water (4×50 mL) and once with brine (1×50 mL) and finally dried over anhydrous sodium sulphate. The red ether solution was then filtered through CELITE® and washed with ether. The solvent was removed under vacuum to afford 2-trichloroacetylpyrrole (Example 1A, 72 g, 91% yield).) as an ash colored solid (72 g, 91% yield). LC-MS, [M−H]+=212. 1H NMR (DMSO-d6, 300 MHz): δ 9.63 (brs, 1H), 7.39 (m, 1H), 7.19 (m, 1H), 6.40 (m, 1H). to reflux during addition Refluxing The layers were separated the red organic layer was washed four times with water (4×50 mL) once with brine (1×50 mL) and finally dried over anhydrous sodium sulphate The red ether solution was then filtered through CELITE® washed with ether The solvent was removed under vacuum

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 2,2,2-Trichloro-1-(1H-pyrrol-2-yl)-ethanone 57b (32 g, 151.8 mmol) was dissolved in 250 mL of dichloromethane followed by dropwise addition of a solution of iodine monochloride (25 g, 153 mmol) in 125 mL of dichloromethane. Upon completion of the addition, the reaction mixture was stirred at room temperature for 2 hours. The reaction was monitored by TLC until the disappearance of the starting materials. The mixture was washed with saturated aqueous sodium carbonate, aqueous sodium thiosulfate (2 M) and saturated brine successively, dried over anhydrous magnesium sulfate, filtered to remove the drying agent and concentrated under reduced pressure. The residue was purified by silica gel column chromatography to obtain the title compound 2,2,2-trichloro-1-(4-iodo-1H-pyrrol-2-yl)-ethanone 57c (47 g, yield 92%) as a yellow solid. Upon completion of the addition The mixture was washed with saturated aqueous sodium carbonate, aqueous sodium thiosulfate (2 M) and saturated brine successively dried over anhydrous magnesium sulfate filtered to remove the drying agent concentrated under reduced pressure The residue was purified by silica gel column chromatography