反应详情

温度

0 °C

The title product from Example 1 (0.50 g, 1.45 mmol) was dissolved in methylene chloride (10 mL) and chilled to 0° C. 1-chloroethyl chloroformate (0.156 mL, 1.45 mmol) was added via syringe. The mixture was allowed to come to room temperature and then refluxed 3 hours. Additional 1-chloroethyl chloroformate (0.1 mL, 0.93 mmol) was added and the mixture was further refluxed overnight. Methanol (10mL) was added and the reaction was refluxed for 2 hours. The mixture was concentrated and the residue was taken up in methylene chloride and extracted with 1N NaOH and brine. The organic phase was dried, concentrated onto silica gel, and flash chromatographed (1×4 inches silica gel). Gradient elution with ethyl acetate/hexane of from 1: 1 to 100% ethyl acetate followed by elution with 2 to 10% ethanol/0.1% ammonium hydroxide/ethyl acetate gave recovered unweighed starting material. Continued elution with 15% methanol/0.1% ammonium hydroxide/ethyl acetate gave 0.32 g of the title product as a clear colorless oil which partially crystallized on standing. Trituration with ether gave 0.13 g (27%) of the title compound as white crystals: mp 141.5°-144° C.; 1H NMR δ 8.58 (br s, 1H), 8.04 (br s, 1H), 7.95 (dd, J=8, 1.5 Hz, 2H), 7.84 (d, J=9 Hz, 1H), 7.68 (dd, J=2, 9 Hz, 1H), 7.62-7.49 (m, 4H), 7.37 (t, J=8 Hz, 1H), 7.12 (d, J=7 Hz, 1H), 3.32-3.22 (m, 5H), 3.16 (br s, 3H), 2.40 (br s, 1H, exchanges with D2O). HRMS m/e calculated for C21H21N3O: 331.1680. Observed m/e: 331.1682.

1. customto come to room temperature
2. temperaturerefluxed 3 hours
3. temperaturethe mixture was further refluxed overnight
4. temperaturethe reaction was refluxed for 2 hours
5. concentrationThe mixture was concentrated
6. extractionextracted with 1N NaOH and brine
7. customThe organic phase was dried
8. concentrationconcentrated onto silica gel, and flash
9. customchromatographed (1×4 inches silica gel)
10. washGradient elution with ethyl acetate/hexane of from 1
11. wash1 to 100% ethyl acetate followed by elution with 2 to 10% ethanol/0.1% ammonium hydroxide/ethyl acetate
12. customgave
13. customrecovered unweighed
14. washelution with 15% methanol/0.1% ammonium hydroxide/ethyl acetate