Cyanamide → HCID 86624874, compound

Temperature

100 °C

To 8-oxabicyclo[3.2.1]oct-6-en-2-one (prepared as described in Vogel et al. Tetrahedron 1993, 49 (8), 1649-1664) (0.5 g, 4.0 mmol) in cyclohexane (3 mL) in a sealable tube was added pyrrolidine (1.7 mL, 20.1 mmol) followed by MgSO4 (4.8 g, 40.3 mmol). The tube was sealed and the mixture was warmed to 100° C. and stirred for 16 hours. The reaction mixture was cooled to ambient temperature, filtered and the filtrate was concentrated under reduced pressure. The residue was dissolved in 10 mL methanol, sulfur (0.13 g, 4.0 mmol) was added and the mixture stirred for 20 min. Cyanamide (0.17 g, 4.0 mmol) was then added and the mixture stirred at ambient temperature for 48 hours. The reaction mixture was concentrated under reduced pressure and purified by flash column chromatography (SiO2, 50% hexanes in ethyl acetate) to give the title compound (90 mg, 0.5 mmol, 12% yield). 1H NMR (300 MHz, CDCl3) δ ppm 2.30 (d, J=16.3 Hz, 1H) 3.21 (ddd, J=16.4, 6.0, 1.0 Hz, 1H) 4.64-4.77 (m, 2H) 5.12 (dd, J=5.9, 1.9 Hz, 1H) 5.25-5.29 (m, J=1.9, 1.9 Hz, 1H) 6.00 (dd, J=5.9, 1.9 Hz, 1H) 6.63 (dd, J=5.6, 1.5 Hz, 1H); MS (DCI/NH3) m/z 181 (M+H)+.

1. customThe tube was sealed
2. temperatureThe reaction mixture was cooled to ambient temperature
3. filtrationfiltered
4. concentrationthe filtrate was concentrated under reduced pressure
5. dissolutionThe residue was dissolved in 10 mL methanol
6. stirringthe mixture stirred for 20 min
7. stirringthe mixture stirred at ambient temperature for 48 hours
8. concentrationThe reaction mixture was concentrated under reduced pressure
9. custompurified by flash column chromatography (SiO2, 50% hexanes in ethyl acetate)

ORD record

ord-e8a47e9b3a0e4b0f851cef832baf40fd

Source dataset

uspto-grants-2014_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08735434B2