反应详情

To a solution of 1.0 g of 3b prepared as above in 35 ml of EtOH there was added 33 ml of 2N NaOH and the reaction mixture stirred overnight at room temperature. The solution was neutralized with HCl or alternatively with Dowex 50 (H+), filtered, and the resin washed thoroughly with aqueous alcohol. After evaporation of the combined filtrates, the residue was passed through a silica gel column and the product eluted with methylene chloride-methanol (15:1) to yield 0.45 g of 4b. It was recrystallized with some difficulty from methylene chloride, M.p. 113° C. UV(pH 1): λ max 266 nm (10,600); (pH 11): λ max 267 nm (7700). NMR(CHCl3): δ 3.53-3.69 (m, 7H, CH2 at C5, CH2OH and tert. H overlap), 5.02 (s, 2H, CH2 of OBzl), 5.20 (s, 2H, CH2 at N1 ), 6.80-7.44 (m, 10H, ArH and C6 -H overlap).

1. filtrationfiltered
2. washthe resin washed thoroughly with aqueous alcohol
3. customAfter evaporation of the combined filtrates
4. washthe product eluted with methylene chloride-methanol (15:1)