Chlorosuccinimide → Tert-butyl 3-(phenylethynyl)-1-oxa-2,8-diazaspiro[4.5]dec-2-ene-8-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a solution of Compound 1a (0.35 g, 2.41 mmol) in 3 mL of DMF stirred at r.t. was added N-chlorosuccinimide (0.386 g, 2.89 mmol) and the solution became orange coloured. After 2 h stirring, the solution became yellow and, after additional 2 h stirring, it was cooled to 0° C. and a solution of tert-butyl 4-methylenepiperidine-1-carboxylate (143 mg, 0.73 mmol) in 0.5 mL of DMF was added, followed by a solution of TEA in 0.5 mL of DMF. The cooling bath was removed and the reaction mixture was stirred at r.t. for 2 days. Afterwards, the reaction mixture was diluted with cold water, extracted with EtOAc. The extracts were washed with brine, dried over Na2SO4, evaporated to dryness in vacuo. The crude was purified by automated flash chromatography (SP1®TM-Biotage; gradient Petroleum Ether-EtOAc from 95:5 to 7:3) affording 210 mg of the title product. Yield: 85.5%.

Provenance & Evidence