N-Iodosuccinimide → 4-Tert-Butyl-2-(4-methyl-benzoylamino)-4H-pyrrolo[2,3-d]thiazole-6-carboxylic acid ethyl ester

Participants

Reaction Conditions

Reaction Steps

4-Methyl-benzoyl isothiocyanate (4.5 ml, 29.5 mmol) was added neat, via syringe under N2 blanket, to a stirred solution of 5-amino-1-tert-butyl-1H-pyrrole-3-carboxylic acid ethyl ester (5.6 g, 26.6 mmol) in anhydrous THF (270 ml), and brought to reflux for 1.5 hours. The solution was chilled to 0° C., then neat N-iodosuccinimide (6.6 g, 29.3 mmol) was added, and the solution was allowed to stir and warm to ambient temperature overnight for 16 hours. Reaction was slowly poured into a stirred 10% (w/v) sodium metabisulfite aqueous solution (200 ml), then extracted with ethyl acetate, dried (MgSO4), and flash chromatographed (silica gel, 25% (v/v) EtOAc/hexanes). Isolated product was crystallized from ethyl acetate/hexanes to afford 4.2 g (41%) of white powder, mp. 200-201° C. MS:M+H=386.

Provenance & Evidence