反应详情

lithium aluminum hydride (0.21 g, 5.40 mmol) was suspended in tetrahydrofuran (15 ml), and under an ice cooling, a solution (5 ml) of ethyl 2-methyl-1,2,3,4-tetrahydrobenzo[4,5]imidazo[1,2-a]pyrazine-8-carboxylate (0.70 g, 2.70 mmol) prepared in the Step 38-1-6 in tetrahydrofuran was slowly added dropwise to the suspension. After the mixture was stirred for 30 minutes under an ice cooling, and a saturated sodium bicarbonate solution was slowly added to the mixture under an ice cooling. Ethyl acetate was slowly added to the resulting mixture, and the precipitate was removed by filtration. The residue separated by filtration was carefully washed with chloroform. The washings and the filtrate were concentrated together. The concentrate was purified by silica gel column chromatography (chloroform:methanol=10:1 to 5:1) to give the title compound (0.56 g, 96%) as a white powder.

1. additionwas slowly added dropwise to the suspension
2. customthe precipitate was removed by filtration
3. customThe residue separated by filtration
4. washwas carefully washed with chloroform
5. concentrationThe washings and the filtrate were concentrated together
6. customThe concentrate was purified by silica gel column chromatography (chloroform:methanol=10:1 to 5:1)