反应详情

温度

0 °C

Glycine (Intermediate 32, 10 g, 48 mmol) was dissolved in acetic acid (50 ml) and water (5 ml). The solution was cooled to 0° C. and sodium nitrite (3.67 g, 53 mmol) in water (10 ml) was added such that the temperature did not rise above 5° C. The yellow solution turned red then brown, and was stirred at 0° C. for 1 h. The mixture was cooled to -5° C. and zinc powder (12.6 g, 193 mmol) was added very slowly such that the temperature did not rise above 0° C. The mixture was stirred at 0° C. for 5 h then poured into water (400 ml) and extracted with ethyl acetate (3×150 ml). The combined, dried (Na2SO4) organic extracts were concentrated in vacuo to give a dark yellow oil. The crude material was purified by chromatography on silica (500 g) eluted with chloroform-ethanol 98:2 to give the title compound (Intermediate 33, 1.4 g, 13%) as a yellow oil.

1. customdid not rise above 5° C
2. temperatureThe mixture was cooled to -5° C.
3. customdid not rise above 0° C
4. stirringThe mixture was stirred at 0° C. for 5 h
5. extractionextracted with ethyl acetate (3×150 ml)
6. dry with materialdried (Na2SO4) organic extracts
7. concentrationwere concentrated in vacuo
8. customto give a dark yellow oil
9. customThe crude material was purified by chromatography on silica (500 g)
10. washeluted with chloroform-ethanol 98:2