Iodine → 2,2,2-trichloro-1-(4-iodo-1H-pyrrol-2-yl)ethan-1-one

Participants

Reaction Conditions

Reaction Steps

The title compound was prepared from 2-(trichloroacetyl)pyrrole according to the method of Bélanger, Tetrahedron Lett., 1979, 2505. Thus, iodine (12.0 g, 47.2 mmol) was added portionwise (approximately 1 g per portion) over 0.17 h to a magnetically stirred mixture of silver trifluoroacetate (11.0 g, 49.8 mmol) and 2-(trichloroacetyl)pyrrole (10.0 g, 47.1 mmol) in dry chloroform (70 ml) maintained at 0° C. (ice-bath). After addition was complete the reaction mixture was allowed to warm to 18° C. and stirred at this temperature for a further 2 h. The resultant suspension was filtered through a sintered glass funnel (No. 3 porosity) and the filtrate washed with Na2S2O5 (1×80 ml of 5% w/v aqueous solution) and water (2×80 ml) then dried (MgSO4), filtered and concentrated under reduced pressure. The solid residue thus obtained was treated with hexane/ether (50 ml of a 4:1 v/v mixture) and the resulting suspension stirred at 18° C. for 5 h then the solid was filtered off to give the title compound (13.1 g, 82%) as a cream solid, m.p. 129-130° C. (lit. m.p. 128-130° C.). 1H n.m.r. d 9.45, broad s, 1H; 7.44, dd, J 2.6 and 1.3 Hz, 1H; 7.19, dd, J 2.6 and 1.3 Hz, 1H.

Provenance & Evidence