Piperazine → 4-(4-chloro-benzenesulfonyl)-6-methyl-8-piperazin-1-yl-3,4-dihydro-2H-benzo[1,4]oxazine

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Reaction Conditions

Reaction Steps

A three neck flask was charged with tris(dibenzylideneacetone)dipalladium(0) (9.1 mg, 0.001 mmol, 2 mol % Pd), (±)-2,2′-bis(diphenylphosphino)-1,1′-binaphthyl (15.5 mg, 0.025 mmol, 5 mol %), and sodium-tert-butoxide (67 mg, 0.7 mmol) and flushed with nitrogen. A solution of 8-bromo-4-(4-chloro-benzenesulfonyl)-6-methyl-3,4-dihydro-2H-benzo[1,4]oxazine (201 mg, 0.5 mmol) and piperazine (129 mg, 1.5 mmol) in toluene (5 mL) was added. The mixture was heated to 95° C. and stirred for 18 hours. The mixture was cooled to room temperature, taken up in ethyl acetate and filtered. The organic phase was washed with water (2×20 mL) and extracted into 10% aqueous HCl (2×20 mL). The combined aqueous extracts were basified with solid potassium carbonate and extracted into ethyl acetate (2×20 mL). The combined organic extract was dried (K2CO3), filtered and concentrated to give the title compound as an oil (163 mg, 79.6%). The hydrochloride salt was prepared from ethanol-hydrogen chloride. MS: MH+=408. M.p. 147.9-152.9° C.

Provenance & Evidence