Potassium Hydroxide → Tert-butyl 4-[2-(1-benzothien-2-yl)-1-hydroxyethyl]piperazine-1-carboxylate

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Reaction Conditions

Reaction Steps

A 50 mL round bottom flask was charged with 2-(2,2-dibromo-vinyl)-benzo[b]thiophene (1.0 g, 3.17 mmol), tert-butyl 1-piperazinecarboxylate (0.09 g, 4.76 mmol) and potassium hydroxide (0.71 g, 12.5 mmol). A solution of tetrahydrofuran:water (4:1) was added and the solution was heated to 70° C. for 18 hours. At the end of this time the solution was concentrated and the residue was diluted with a 2N aqueious solution of hydrochloric acid and extracted 3 times with ethyl acetate. The ethyl acetate was dried and concentrated and the residue subjected chromatography via Biotage (FLASH 40 M, silica, 60% ethyl acetate/hexane) to yield 0.75 g (65%) of tert-butyl 4-[2-(1-benzothien-2-yl)-1-hydroxyethyl]piperazine-1-carboxylate as an off white solid. MS (ES) m/z 305.1; HRMS: calcd for C19H26N2O3S, 362.1664. found (ESI, [M+H]+), 361.1569.

Provenance & Evidence