Diethyl disulfide → (4R,9aR)-7-Ethylsulfanyl-4,6-dimethyl-3,4,9,9a-tetrahydro-1H-2,4a,5-triaza-fluorene-2-carboxylic acid tert-butyl ester

Participants

Reaction Conditions

Reaction Steps

A solution of 0.50 g (1.31 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 30 mL diethyl ether was cooled to −100° C. and 1.05 mL tert-butyl-lithium (1.57 mmol; 1.5M solution in n-pentane) was added dropwise. After 15 min. diethyl disulfide was added and the reaction was stirred at −78° C. for 1 h. The reaction mixture was quenched with 10% aqueous citric acid solution and extracted three times 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 over silica gel (0.030–0.063 mm) with ethyl acetate:n-hexane (1:4) as eluant to give the product as a light yellow solid (57.2%).

Provenance & Evidence