Bicyclo[2.2.1]heptane-1-methanesulfonic acid, 7,7-dimethyl-2-oxo-, (1S)- → 1-Benzylideneamino-3-propyltetrahydrocyclopenta[d]imidazol-2,5(1H,3H)-dione

Participants

Reaction Steps

An acetone solution (150 ml) of the compound of step (d) (21 g) was stirred at 15° C. while camphorsulphonic acid (2.5 g) was added portionwise over 10 minutes. After 4 hours, the mixture was concentrated in vacuo, water (150 ml) and chloroform (100 ml) added and the organic phase separated. The latter was washed with dilute sodium bicarbonate (100 ml), separated and concentrated in vacuo to give the desired product as a brown oil (21.0 g).

Provenance & Evidence