Ethanol → 6-Oxa-7-aza-bicyclo[3.2.2]non-8-ene hydrochloride

Temperature

-20 °C

To a solution of 16.8 g (0.149 mol) cyclohexanone oxime in 240 ml methylene chloride was slowly added at 0° C. 19.4 g (0.178 mol) tert.-butyl-hypochlorite. The resulting dark blue solution was cooled to −20° C. and then 30 ml ethanol and 20.0 g (0.212 mol) 1,3-cycloheptadiene were added and the mixture was stored in a freezer at 5° C. for 2 days until the blue color had disappeared. The reaction mixture was added to 30 ml isopropanol and then 300 ml diethyl ether and after stirring for 3 h the resulting precipitate was isolated by suction to yield 18.6 g of 6-oxa-7-aza-bicyclo[3.2.2]non-8-ene hydrochloride. 9.0 g (0.072 mol) of this material were hydrogenated with palladium on activated carbon at 5 bar hydrogen. After complete conversion the catalyst was filtered off and a solution of 30 ml 4 M hydrochloric acid in dioxane was added. After evaporation the residue was crystallized from 20 ml isopropanol and 500 ml diethyl ether giving 7.5 g cis-4-amino-cycloheptanol as hydrochloride.

1. customwas isolated by suction

ORD record

ord-2a4614ddd9904720a15f96b1b0924a17

Source dataset

uspto-grants-2014_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08742116B2