Nitroethane → HCID 14090006, compound

Temperature

25 °C

Under an inert atmosphere a solution of nitroethane (5.36 g, 5.1 ml, 71.4 mmol) in ether (20 ml) was treated at room temperature with a solution of cyclohex-2-enone (6.73 g, 6.78 ml, 70 mmol) in ether (120 ml) followed by the addition of triethylamine (70.8 mg, 97.6 μl, 700 μmol) and the dropwise addition (appr. 1 minute) of phenyl isocyanate (17.0 g, 15.6 ml, 143 mmol). The clear solution was stirred at 25° C. for 48 hours while solid started to precipitate after 2 hours. For the workup, the solid material was filtered and washed three times with ether. The yellow filtrate was evaporated, then the yellow crude product was suspended in dichloromethane (30 ml), the solid was filtered off and washed three times with dichloromethane. After evaporation of the filtrate the crude product was purified by flash chromatography on silica gel using a gradient of heptane and ethyl acetate=5:1 to 4:1 to 1:1 as the eluent. The rac-(3aR,7aR)-3-methyl-5,6,7,7a-tetrahydrobenzo[d]isoxazol-4(3aH)-one (7.27 g, 68% yield) was obtained as an orange liquid. MS: m/z=154.1 [M+H]+. In addition, the rac-(3aR,7aS)-3-methyl-3a,5,6,7a-tetrahydro-4H-benzo[d]isoxazol-7-one (0.52 g, 4.9% yield) was obtained as a light brown solid. MS: m/z=154.1 [M+H]+.

1. customto precipitate after 2 hours
2. filtrationFor the workup, the solid material was filtered
3. washwashed three times with ether
4. customThe yellow filtrate was evaporated
5. filtrationthe solid was filtered off
6. washwashed three times with dichloromethane
7. customAfter evaporation of the filtrate the crude product
8. customwas purified by flash chromatography on silica gel using a gradient of heptane and ethyl acetate=5:1 to 4:1 to 1:1 as the eluent

ORD record

ord-f31edecc480f4dd9bb23cbc45b832900

Source dataset

uspto-grants-2015_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09181232B2