Methanol → Benzyl (3-oxocyclobutyl)carbamate

Temperature

-78 °C

N-(Benzyloxycarbonyl)-3-methylenecyclobutanamine (4 g, 18.4 mmol) from Step A of Example 5, 34 mL of methanol and 136 mL of methylene chloride were mixed together and cooled to -78° C. under a nitrogen atmosphere. Ozone was bubbled through the mixture for approximately 20 minutes and then the reaction mixture was flushed with nitrogen for approximately 10 minutes. Dimethyl sulfide (17 mL) was added to the reaction mixture and the reaction mixture was then stirred for 0.5 h at -78° C. and 0.5 h at ambient temperature. The reaction mixture was concentrated under reduced pressure to a syrup. The syrup (6.2 g) was purified on a 1.5×40 cm silica gel column, rinsed with hexane and eluted @ 5 psi with 400 mL of 25% acetone in hexane to give 3.74 g (93% yield) of the title compound; MS DCI-NH3M/Z: 237 (M+NH4)+ ; 1H NMR (CDCl 3) δ 3.10 (m, 2H), 3.43 (m, 2H), 4.31 (m, 1H), 5.13 (s, 2H), 7.45 (s, 5H).

1. customOzone was bubbled through the mixture for approximately 20 minutes
2. customthe reaction mixture was flushed with nitrogen for approximately 10 minutes
3. additionDimethyl sulfide (17 mL) was added to the reaction mixture
4. concentrationThe reaction mixture was concentrated under reduced pressure to a syrup
5. customThe syrup (6.2 g) was purified on a 1.5×40 cm silica gel column
6. washrinsed with hexane
7. washeluted @ 5 psi with 400 mL of 25% acetone in hexane

ORD record

ord-172fe4077e1e42b09cf936e4e5ad0591

Source dataset

uspto-grants-1993_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05246931