Sodium Carbonate → (4R,9aR)-4,6,7-Trimethyl-3,4,9,9a-tetrahydro-1 H-2,4a,5-triaza-fluorene-2-carboxylic acid tert-butyl ester

Participants

Reaction Conditions

Reaction Steps

To a solution of 0.30 g (0.78 mmol) (4R,9aR)-7-bromo-4,6-dimethyl-3,4,9,9a-tetrahydro-1H-2,4a,5-triaza-fluorene-2-carboxylic acid tert-butyl ester (example 6, intermediate) in 15 mL dimethoxyethane was added 9 mg tetrakis(triphenylphosphine)palladium. After 20 min. 0.25 g (2.35 mmol) sodium carbonate in 8 mL water and 132 μl (0.94 mmol) trimethylboroxine were added and the reaction was stirred at 100° C. for 3 h. The reaction was cooled to room temperature then poured into 1M aqueous sodium hydroxide solution and extracted twice with ethyl acetate. The combined organic layers were washed with brine, dried over magnesium sulfate, filtered and evaporated. The residue was purified by column chromatography on silica gel with ethyl acetate:n-hexane (1:2) as eluant to give the product as a light yellow oil (66.0%).

Provenance & Evidence