Hydrochloric Acid → Tropane

Participants

Reaction Conditions

Reaction Steps

The anhydroecgonine methyl ester 1 (leq.) is dissolved in 25 ml of anhydrous ether and then added to 5 eq. of (methylphenyl) magnesium bromide at −40° C. After 3 hours of mechanical stirring, the mixture is cooled to −78° C. and treated drop by drop with a solution of 5 ml of trifluoroacetic acid diluted in 25 ml of anhydrous ether. After one hour's stirring, the mixture is brought to 0° C. and then treated with 70 ml of water and 26 ml of concentrated HCl. The aqueous phase is then treated with NH4OH and extracted with ether (3×40 ml). The different organic phases are collected, washed in brine, dried on Na2SO4 and evaporated to produce compound 2 with a yield of 30%.

Provenance & Evidence