反应详情

温度

0 °C

In a 50 mL 3-neck RBF equipped with N2-bubbler and thermo pocket, tert-butyl (2-hydroxy-5-nitrophenyl)carbamate (2.0 g), benzyl alcohol (1.02 g) and triphenyl phosphine (2.48 g) were taken in 10 mL DCM. The reaction mixture was cooled to 0° C. Diethyl azodicarboxylate (1.65 g) was dissolved in 10 mL DCM was added dropwise in the reaction. The reaction mixture was stirred at room temperature for 24 h. The reaction mixture was monitored on TLC using hexane:ethyl acetate (6:4) as mobile phase. After completion, the reaction was poured into water and extracted with DCM (3×50 mL). The DCM layer was washed with brine solution, dried over sodium sulfate and concentrated under reduced pressure at 40° C. Purification was carried out by column chromatography. Desired product eluted with 5% ethyl acetate in hexane to give, after concentration, 1.03 g of tert-butyl (2-(benzyloxy)-5-nitrophenyl)carbamate. 1H NMR: DMSO-d6 (400 MHz) 1.48 (s, 9H), 5.34 (s, 2H), 7.26 (d, 1H, J=9.2), 7.35 (m, 1H), 7.41 (m, 2H), 7.54 (d, 2H, J=6.8), 7.95 (dd, 1H, J=2.8, 9.2), 8.51 (s, 1H), 8.64 (d, 1H, J=2.8).

1. additionwas added dropwise in the reaction
2. extractionextracted with DCM (3×50 mL)
3. washThe DCM layer was washed with brine solution
4. dry with materialdried over sodium sulfate
5. concentrationconcentrated under reduced pressure at 40° C
6. customPurification
7. washDesired product eluted with 5% ethyl acetate in hexane
8. customto give
9. concentrationafter concentration, 1.03 g of tert-butyl (2-(benzyloxy)-5-nitrophenyl)carbamate