Cyclohexanone Oxime → 2-Oxa-3-azabicyclo[2.2.2]oct-5-ene hydrochloride

Temperature

-20 °C

To a solution of 30.0 g (0.265 mol) of cyclohexanone oxime in 300 ml of methylene chloride and 38 ml of ethanol was slowly added at 0° C. 34.5 g (0.318 mol) of tert.-butyl-hypochlorite. The resulting dark blue solution was cooled to −20° C. and then 31.9 g (0.398 mol) of 1,3-cyclohexadiene 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 concentrated to 50% of its volume and then 600 ml of diethyl ether were slowly added. After stirring overnight the resulting precipitate was isolated by suction to yield 29.0 g of 2-oxa-3-aza-bicyclo[2.2.2]oct-5-ene hydrochloride. 5.0 g (0.045 mol) of this material were hydrogenated with 3.0 g (0.013 mol) platinum oxide at 2 bar hydrogen pressure. After 7 h the catalyst was filtered off and a solution of 20 ml 4 M hydrochloric acid in dioxane was added. After evaporation the residue was recrystallized from 30 ml isopropanol giving 3.1 g of cis-4-aminocyclohexanol hydrochloride.

1. concentrationThe reaction mixture was concentrated to 50% of its volume
2. addition600 ml of diethyl ether were slowly added
3. customwas isolated by suction

ORD record

ord-b91830613a34432fbd137e4ea73e0b18

Source dataset

uspto-grants-2013_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08609691B2