Nitroethane → HCID 13012663, compound

Temperature

25 °C

Under an inert atmosphere a solution of nitroethane (4.66 g, 4.44 ml, 62.1 mmol) in ether (15 ml) was treated at room temperature with a solution of cyclopent-2-enone (5 g, 5.1 ml, 60.9 mmol) in ether (90 ml) followed by the addition of triethylamine (70.8 mg, 97.6 μl, 700 μmol) and the dropwise addition of phenyl isocyanate (14.8 g, 13.6 ml, 124 mmol). The light yellow solution was stirred at 25° C. during the weekend. For the workup, the off-white suspension was filtered and washed three times with ether. The filtrate was evaporated, then the crude product was triturated in dichloromethane (15 ml), the solid was filtered off and washed with dichloromethane. After evaporation of the orange-colored filtrate the crude product was purified by flash chromatography on silica gel using a gradient of heptane and ethyl acetate=2:1 to 1:2 as the eluent. The rac-(3aR,6aR)-3-methyl-3a,5,6,6a-tetrahydro-cyclopenta[d]isoxazol-4-one (5.95 g, 70% yield) was obtained as yellow liquid. MS: m/z=139 [M]+. In addition, the rac-(3aR,6aS)-3-methyl-3a,4,5,6a-tetrahydro-cyclopenta[d]isoxazol-6-one (0.37 g, 4.3% yield) was obtained as a yellow oil. MS: m/z=139 [M]+.

1. filtrationFor the workup, the off-white suspension was filtered
2. washwashed three times with ether
3. customThe filtrate was evaporated
4. customthe crude product was triturated in dichloromethane (15 ml)
5. filtrationthe solid was filtered off
6. washwashed with dichloromethane
7. customAfter evaporation of the orange-colored filtrate the crude product
8. customwas purified by flash chromatography on silica gel using a gradient of heptane and ethyl acetate=2:1 to 1:2 as the eluent

ORD record

ord-6b79df49a5544125bcef16c55880bb73

Source dataset

uspto-grants-2015_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09181232B2