Ammonia → HCID 11472050, compound

Participants

Reaction Conditions

Reaction Steps

To a suspension of potassium thiocyanate (8.55 g, 88 mmol) in ethyl acetate (100 mL) cooled to 0° C. was added dropwise a solution of 9-fluorenylmethoxycarbonyl chloride (20.7 g, 80 mmol) in ethyl acetate (100 mL) over a period of 15 min. The resulting suspension was allowed to warm to ambient temperature overnight with stirring. The formed solid was filtered off and the filtrate was concentrated in vacuo to afford an orange oil. Without further purification, the oil was dissolved in ethanol (50 mL) and treated by dropwise addition with a cold solution of ammonia in ethanol (7N, 91 mL, 637 mmol). A precipitate formed upon addition of the ammonia solution. The suspension was stirred vigorously at 0° C. for 15 min and then the solids were filtered off, washed with cold ethanol (3×20 mL) and dried to afford N-Fmoc-thiourea (16.8 g, 70%) as an off-white solid: EI-HRMS m/e calcd for C16H14N2O2S (M+) 298.0776, found 298.0770.

Provenance & Evidence