Lithium Hydroxide → HCID 86616777, compound

Participants

Reaction Steps

Lithium hydroxide (63 mg, 1.49 mmol) was added to a solution of methyl N-(tert-butoxycarbonyl)-S-{2-[(cyclopropylmethyl)amino]-1-phenylethyl}-D-cysteinate (507 mg, 1.24 mmol) in tetrahydrofuran (10 mL) and water (2 mL). After 1 h, then mixture was concentrated and azeotroped with toluene (3×) to give the crude acid. Diphenylphosphoryl azide (0.53 ml, 2.48 mmol) was added to a solution of the crude acid and 4-methylmorpholine (0.20 mL, 1.86 mmol) in N,N-dimethylformamide (25 mL). After 4 h, the mixture was concentrated and water was added. The mixture was extracted with ethyl acetate, and the organic layer was washed with water (2×) and saturated brine, dried over magnesium sulfate, filtered, and concentrated. Purification by silica gel chromatography (5% ethyl acetate/hexanes→20% ethyl acetate/hexanes) gave the title compound (149 mg). MS 377 (M+1).

Provenance & Evidence