反应详情

Compound 33 (150 mg, 0.3 mmol) was suspended in dry acetone (50 mL) then methanol was added until a clear solution was formed (approx. 15 mL). p-Toluenesulfonic acid monohydrate (25 mg) was added along with molecular sieves (5 A) and the reaction mixture was stirred for 48 h at room temperature. After this time, the reaction mixture was filtered, silica gel (20 mL) was added and the solvent was removed under reduced pressure. This silica gel with the reaction mixture adsorbed was added to the top of a silica gel flash chromatography column. Compound 37 (120 mg, 81%) was isolated by flash chromatography (silica gel, 10:1:0.1 chloroform/methanol/concentrated ammonium hydroxide) as a yellow solid. 1H NMR (300 MHz, DMSO-d6) δ 1.30 (s, 3H), 1.34 (s, 3H), 1.52 (br s, 4H), 2.56 (br s, 2H), 3.13 (br s, 2H), 3.71 (m, 1H), 3.92 (m, 2H), 4.08 (m, 1H), 4.45 (m, 1H), 6.64 (br s, 2H), 6.82 (m, 2H), 7.12 (m, 2H). APCI MS m/z=492 [C22H30ClN7O4+H]+.

1. customwas formed (approx. 15 mL)
2. filtrationAfter this time, the reaction mixture was filtered
3. additionsilica gel (20 mL) was added
4. customthe solvent was removed under reduced pressure
5. additionThis silica gel with the reaction mixture adsorbed was added to the top of a silica gel flash chromatography column