4-Methylmorpholine → (1RS,2S)-2-{(3RS)-4-Acetyl-3-isopropyl-2-oxo-6-phenyl-1,2,3,4-tetrahydropyrazin-1-yl}methylcarbonylamino-3-phenyl-1-(1,3-thiazol-2-yl)-1-propanol

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Reaction Conditions

Reaction Steps

N-Methylmorpholine (66.4 μl) is added to a solution of {(3RS)-4-acetyl-3-isopropyl-2-oxo-6-phenyl-1,2,3,4-tetrahydropyrazin-1-yl}acetic acid (162 mg, Reference compound No. 51-1) in tetrahydrofuran (2.5 ml). The mixture is cooled to −10° C., isobutyl chloroformate (65.4 μl) is added to the mixture, and the whole is stirred for 15 minutes. A mixed solution of (1RS,2S)-2-amino-3-phenyl-1-(1,3-thiazol-2-yl)-1-propanol hydrochloride (150 mg, Reference compound No. 10-2) and N-methylmorpholine (132.6 μl) in tetrahydrofuran (2.5 ml) and dimethyl sulfoxide (1 ml) is added thereto, and the whole is stirred overnight. Water is added to the reaction mixture, and the whole is extracted with ethyl acetate. The extract is washed with an aqueous sodium hydrogencarbonate solution, water and saturated brine successively and dried over magnesium sulfate. The extract is concentrated under reduced pressure, and the resulting residue is purified by column chromatography to give the titled compound (162.9 mg).

Provenance & Evidence