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

Participants

Reaction Steps

Triethylamine (2.60 ml) is added to a solution of (2S)-2-{(3RS)-4-acetyl-3-isopropyl-2-oxo-6-phenyl-1,2,3,4-tetrahydropyrazin-1-yl}methylcarbonylamino-3-phenyl-1-propanol (1.37 g, Compound No. 6-1) in dimethyl sulfoxide (16 ml). A sulfur trioxide-pyridine complex (1.7 g) is added to the mixture, and the whole is stirred overnight. Water is added to the reaction mixture, and the whole is stirred for one hour and extracted with ethyl acetate. The extract is washed with a saturated aqueous ammonium chloride solution, water and saturated brine successively and dried over anhydrous magnesium sulfate. The extract is concentrated under reduced pressure, and the resulting residue is purified by silica gel column chromatography to give the titled compound (631 mg).

Provenance & Evidence