tert-Butyl carbamate → tert-butyl N-(4-fluoropyridin-2-yl)carbamate

Participants

Reaction Conditions

Reaction Steps

2-chloro-4-fluoropyridine (132 mg, 1 mmol), tert-butyl carbamate (123 mg, 1.05 mmol), CESIUM CARBONATE (652 mg, 2.00 mmol) ,TRIS(DIBENZYLIDENEACETONE)DIPALLADIUM (36.6 mg, 0.04 mmol) and 9,9-DIMETHYL-4,5-BIS(DIPHENYLPHOSPHINO)XANTHENE (46.3 mg, 0.08 mmol) were suspended in 1,4-dioxane (2.5 ml) ,degased with argon and heated to 90 °C for 4 hours. After cooling the reaction was quenched with water and extracted with ethyl acetate ( x 2 ). The combined organic phases were washed with water , a saturated aqueous solution of brine , dried over magnesium sulfate , concentrated then purified by preparative HPLC using a Waters X-Bridge reverse-phase column (C-18, 5 microns silica, 19 mm diameter, 100 mm length, flow rate of 40 ml / minute) and decreasingly polar mixtures of water (containing 0.2% ammonium carbonate) and acetonitrile as eluent. The fractions containing the desired compound were evaporated to dryness to afford tert-butyl 4-fluoropyridin-2-ylcarbamate (41.3 mg, 19.46 %).

Provenance & Evidence