反应详情

A 10 mL round bottom flask fitted with magnetic stirrer and pressure-equalizing dropping funnel was charged with 3 mL of DMF which had been dried by vacuum distillation from CaH2. Methyl 6-hydroxy-2-naphthoate (1.01 g, 5 mmol) and t-butyldimethyl silyl chloride (0.83 g, 5.5 mmol) were added and the atmosphere replaced with nitrogen. A solution of imidazole (0.75 g, 11 mmol) in 3 mL of dry DMF was added via the dropping funnel over 15 minutes, and stirring continued for 4 hours. TLC analysis (SiO2, 5% ethyl acetate/hexane) showed clean conversion to a new material. The solution was poured into 50 mL of 1% aq. Na2CO3 solution and extracted with 3-35 mL portions of pentane. The combined pentane solutions were washed with 25 mL of water, 25 mL of brine and dried over MgSO4. Evaporation of the pentane yielded 1.45 g of slightly yellow solid. Purification by column chromatography on silica using 5% (V/V) ethyl acetate/hexane as eluent afforded 1.4 g (88%) of white solid after recrystallization from pentane: mp 72°-72.5° C.; 1H NMR delta 0.266 (s, 6H), 1.022 (s, 9H), 3.958 (s, 3H), 7.19-8.53 (m, 6H); 13C NMR delta -4.35, 18.23, 25.64, 52,03, 114.74, 122.87, 125.38, 125.62, 126.75, 128.16, 130.87, 130.95, 137.10, 155.69, 167.36; IR (KBr) 2950, 2860, 1715, 1635, 1605, 1480, 1290, 1210 cm1 ; MS m/e (rel. intensity) 316 (33, 285(7), 260 (33), 259 (100), 200 (11), 185 (13), 141 (8). ##STR28##

1. customA 10 mL round bottom flask fitted with magnetic stirrer
2. customhad been dried by vacuum distillation from CaH2
3. extractionextracted with 3-35 mL portions of pentane
4. washThe combined pentane solutions were washed with 25 mL of water, 25 mL of brine
5. dry with materialdried over MgSO4
6. customEvaporation of the pentane
7. customyielded 1.45 g of slightly yellow solid
8. customPurification by column chromatography on silica using 5% (V/V) ethyl acetate/hexane as eluent