反应详情

To 40A (0.1 g, 0.27 mmol) in pyridine (1 mL) at 0° C. was added methyl chloroformate (57 μL, 0.54 mmoL). After 2.0 h of stirring at rt the reaction was acidified with 1M HCl to pH 3-4. The product was extracted with ethyl acetate and was washed with brine and dried over sodium sulfate. After evaporation of the solvent, the crude product was redissolved in ethyl acetate (1.5 mL) and hydrogen chloride (2 mL, 4M in dioxane) was added. The reaction was stirred for 3 h at rt. The solvent was removed and placed on the lyophilizer to give 0.15 g white solid 44A. 1H NMR (400 MHz, Methanol-d4) δ ppm 1.25 (t, J=7.09 Hz, 3H) 1.37 (d, J=6.85 Hz, 3H) 2.13-2.31 (m, 1H) 2.31-2.47 (m, 2H) 2.47-2.63 (m, 1H) 3.36-3.56 (m, 3H) 3.73-3.91 (m, 3H) 5.43 (t, J=7.70 Hz, 1H) 7.66 (dd, J=8.80, 2.20 Hz, 1H) 7.97 (d, J=8.80 Hz, 1H) 8.11 (d, J=1.96 Hz, 1H).

1. extractionThe product was extracted with ethyl acetate
2. washwas washed with brine
3. dry with materialdried over sodium sulfate
4. customAfter evaporation of the solvent
5. dissolutionthe crude product was redissolved in ethyl acetate (1.5 mL)
6. additionhydrogen chloride (2 mL, 4M in dioxane) was added
7. stirringThe reaction was stirred for 3 h at rt
8. customThe solvent was removed