Methanol → 2-methyl-2-{[4-(2-{[(1-phenyl-1H-pyrazol-4-yl)methyl]amino}ethyl)-1,3-thiazol-2-yl]thio}propionic acid tert-butyl ester

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Reaction Steps

2-Methyl-2-{[4-(2-{[(1-phenyl-1H-pyrazol-4-yl)carbonyl]amino}ethyl)-1,3-thiazol-2-yl]thio}propionic acid tert-butyl ester (16.2 g) obtained in Example 451-1 was dissolved in tetrahydrofuran (20 mL), 1 mol/L-borane/tetrahydrofuran complex (160 mL) was added under ice-cooling, and the mixture was stirred at room temperature for 12 hr. The reaction mixture was ice-cooled, and methanol (200 mL) was added dropwise. After warming to room temperature, the mixture was stirred for 1 hr. The reaction mixture was concentrated under reduced pressure, piperidine (60 mL) was added, and the mixture was stirred at 60° C. for 4 hr. The reaction mixture was concentrated under reduced pressure, and the residue was purified by silica gel chromatography (elution solvent; dichloromethane:methanol=20:1 to 10:1) to give the title compound (9.5 g) as a slightly yellow oil.

Provenance & Evidence