Trifluoroacetic acid → 3,4-Dimethoxy-6-methylphenanthren-9-amine

Participants

Reaction Steps

A mixture of 400 ml (2.87M) of trifluoroacetic anhydride and 400 ml (5.22M) of trifluoroacetic acid is added at room temperature under a nitrogen atmosphere to 61.1 g (0.206M) of 3,4-dimethoxy-6-methyl-phenanthrene-9-carboxylic acid and the mixture is stirred for 10 minutes. After the mixture has been cooled to -5°, 16.08 g (0.247M) sodium azide are carefully added in solid form. The mixture is stirred for 2 hours at 0°, poured onto ice, extracted three times with methylene chloride and washed with a solution 1N of sodium hydroxide. The aqueous phases are extracted twice with methylene chloride 2-propanol 8:2. The organic phases are combined, dried and evaporated, to give white crystals. 86 g of the resultant mixted anhydride are warmed for 2 hours under reflux in 800 ml of a solution 2N of sodium hydroxide and 800 ml ethanol and the mixture is evaporated. The residue is washed with water/ice and extracted three times with methylene chloride. The organic phases are combined, dried and evaporated to give the title compound as an oil.

Provenance & Evidence