tert-Butyl piperazine-1-carboxylate → tert-Butyl 4-(4-methylthiazol-5-yl)piperazine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

A solution of 5-bromo-4-methylthiazole (454 mg, 2.55 mmol), N-Boc-piperazine (940 mg, 5.05 mmol), sodium tert-butoxide (492 mg, 5.12 mmol) and dicyclohexyl-[3,6-dimethoxy-2-(2,4,6-thisopropylphenyl)phenyl]phosphane (BrettPhos, 64.9 mg, 0.121 mmol) in anhydrous 1,4-dioxane (9 mL) was flushed with argon for 3 min. Tris(dibenzylideneacetone)dipalladium(0) (106 mg, 0.116 mmol) was added and the mixture was heated in a sealed flask to 70° C. for 2.5 hours. The reaction mixture was cooled to room temperature, diluted with EtOAc, filtered through kieselguhr and the filtrate was concentrated under reduced pressure to yield 1.5 g of a brown oil which was purified by flash chromatography (silica, gradient of 0.5 to 3% methanol in dichloromethane). 267 mg of a light-yellow oil were obtained (0.942 mmol), 37%). MS (ESI) m/z=284.2 [M+1]+.

Provenance & Evidence