反应详情

温度

0 °C

To 90% HNO3 (55.1 g, 0.8 mol) under nitrogen at −30° C. is added 100 mL of trifluoroacetic acid followed by the addition of trifluoroacetic anhydride (100 g, 0.476 mol) over 5 minutes. The above carbamate (1-acetyloxy-indan-2-yl)-carbamic acid methyl ester (1S-trans)) (20.0 g, 0.08 mol) in 34 mL of methylene chloride is added slowly (over 90 min.) keeping the temperature between −30 and −35° C. The reaction is worked up by adding 100 mL of water and warmed to 0° C. to give two layers. The layers are separated and the aqueous layer extracted with methylene chloride. The combined organic extracts are washed with 100 mL of water (pH is adjusted to 8.5 with sodium bicarbonate), and with cold water. The organic layer is dried over MgSO4, filtered and evaporated to give crude product. The crude product is crystallized from ethyl acetate and further precipitated by the addition of heptane to give (1-acetyloxy-6-nitro-indan-2-yl)-carbamic acid methyl ester (1S-trans); mp 164-167° C.

1. customthe temperature between −30 and −35° C
2. customto give two layers
3. customThe layers are separated
4. extractionthe aqueous layer extracted with methylene chloride
5. washThe combined organic extracts are washed with 100 mL of water (pH is adjusted to 8.5 with sodium bicarbonate)
6. dry with materialThe organic layer is dried over MgSO4
7. filtrationfiltered
8. customevaporated
9. customto give crude product
10. customThe crude product is crystallized from ethyl acetate
11. customfurther precipitated by the addition of heptane