反应详情

Ethyl benzothiazole-6-carboxylate (2.10 g, 10.0 mmol) prepared in the Step 36-1-2 was dissolved in dichloromethane (80 ml), and under an ice cooling, a solution (1.5 mol/L) (20 ml, 30.0 mmol) of diisobutylaluminum hydride in hexane was slowly added thereto. The mixture was stirred at a room temperature for one hour, and then ethyl acetate (10 ml) and a saturated sodium bicarbonate solution were added to the mixture. Ethyl acetate and water were added thereto, the resulting mixture was subjected to extraction with ethyl acetate. The extract was dried over anhydrous magnesium sulfate and then concentrated. The residue was purified by silica gel column chromatography (n-hexane:ethyl acetate=1:1) to give the title compound (0.61 g, 37%) as a yellowish-brown oily substance.

1. extractionthe resulting mixture was subjected to extraction with ethyl acetate
2. dry with materialThe extract was dried over anhydrous magnesium sulfate
3. concentrationconcentrated
4. customThe residue was purified by silica gel column chromatography (n-hexane:ethyl acetate=1:1)