Phosgene → HCID 19016507, compound

Participants

Reaction Steps

To a solution of the aminoindole (D1) (0.71 g; 3.78 mM) in dichloromethane (13.5 ml) at 0° C. was added a 12.5% solution of phosgene in toluene (3.28 ml; 3.79 mM). After stirring for 0.5 h, triethylamine (1.15 ml ) was added and stirring was continued for 0.5 h. A solution of 3-aminopyridine (0.34 g; 3.6 mM) in dichloromethane (10 ml) was then added, and stirring continued for 3.5 h at room temperature. Several drops of aqueous sodium hydroxide were added to the reaction mixture which was vigorously stirred for 0.5 h. The reaction mixture was diluted with water and extracted with dichloromethane. The combined organic extracts were washed with brine, dried over sodium sulphate and evaporated to dryness. Chromatography on silica using dichloromethane as eluant afforded the title compound (0.2 g; 17%) which was converted to the hydrochloride salt using hydrogen chloride in ether/ethanol, m.p. 158°-165° C.

Provenance & Evidence