反应详情

A solution of the compound of step (a) (5.0 g, 8.83 mmol) in methanol (100 ml) was hydrogenated over Pearlman's catalyst (1.0 g) at room temperature and at 414 kPa (60 p.s.i.) for 16 hours. The solution was filtered through a pad of celite (trade mark) and concentrated. The crude product was redissolved in hot methanol (20 ml) and granulated at 0° C. for 1 hour. After filtering and washing with methanol (5 ml) the product was dried under vacuum at 50° C. to give the title compound (1.72 g, 49%). m.p. 145-146° C.

1. filtrationThe solution was filtered through a pad of celite (trade mark)
2. concentrationconcentrated
3. dissolutionThe crude product was redissolved in hot methanol (20 ml)
4. filtrationAfter filtering
5. washwashing with methanol (5 ml) the product
6. customwas dried under vacuum at 50° C.