Sodium Hydroxide → HCID 21963089, compound

Participants

Reaction Steps

tert-butyl-1-piperazinecarboxylate (5.94 g, 31.9 mmol, 2.00 equiv) was added to a solution of 1-(trifluoroacetyl)indoline-5-sulfonyl chloride (1-6, 5.00 g, 15.9 mmol, 1 equiv) in dichloromethane (50 mL) at 23° C., and the resulting mixture was stirred for 45 minutes. The brown-colored reaction mixture was concentrated and the resulting tan-colored solid dried in vacuo. A solution of the solid in a mixture of 1,4-dioxane (100 mL) and methanol (30 mL) was treated with aqueous 1N NaOH solution (47.9 mL, 47.9 mmol, 3.00 equiv), and the resulting mixture was stirred for 1 hour. The mixture was concentrated, and the resulting solid suspended in diethyl ether (130 mL) and filtered. The filtered solid was then partitioned between aqueous saturated sodium chloride solution (150 mL) and ethyl acetate (4×85 mL). The organic layer was dried over sodium sulfate and concentrated to provide the tert-butyl 4-(2,3-dihydro-1H-indol-5-ylsulfonyl)piperazine-1-carboxylate (2-1) as an off-white solid. 1H NMR (300 MHz, CDCl3) δ 7.41 (m, 2H), 6.57 (d, 1H, J=8.9 Hz), 3.69 (t, 2H, J=8.6 Hz), 3.50 (t, 2H, J=4.9 Hz), 3.09 (t, 2H, J=8.6 Hz), 2.93 (t, 2H, J=4.9 Hz) 1.42 (s, 9H).

Provenance & Evidence