Ethyl Acetate → 4-[4-(2-fluoro-benzenesulfonyl)-2,2-dimethyl-3,4-dihydro-2H-benzo[1,4]oxazin-8-yl]-piperazine-1-carboxylic acid tert-butyl ester

Participants

Reaction Conditions

Reaction Steps

A solution of 8-bromo-4-(2-fluoro-benzenesulfonyl)-2,2-dimethyl-3,4-dihydro-2H-benzo[1,4]oxazine (450 mg, 1.124 mmol) and 1-Boc-piperazine (209.4 mg, 1.124 mmol) in 5 mL of toluene was added to a warm, degassed mixture of Pd2(dba)3(Tris(dibenzylideneacetone)dipalladium(0), 20.59 mg, 0.022 mmol), BINAP (2,2′-bis(diphenylphosphino)-1,1′-binaphthyl, 35.0 mg, 0.056 mmol) and NaOt-Bu (151.26 mg, 1.57 mmol) in 5 ml of toluene. With stirring, the solution was heated at 90° C. for 2 hours, and then allowed to cool to room temperature. Ethyl acetate was added to the reaction which was then filtered through celite. The filtrate was washed with water (2×15 ml), brine (1×15 ml), and dried over MgSO4, after which the organic fraction was concentrated in vacuo. The resulting residue was purified by flash chromatography (15%–30% Ethyl acetate/Hexane) to give 470 mg (0.93 mmol) of 4-[4-(2-fluoro-benzenesulfonyl)-2,2-dimethyl-3,4-dihydro-2H-benzo[1,4]oxazin-8-yl]-piperazine-1-carboxylic acid tert-butyl ester. MS: (M+H) 506.

Provenance & Evidence