Allyl bromide → tert-Butyl allyl(prop-2-yn-1-yl)carbamate

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Reaction Conditions

Reaction Steps

Sodium hydride (6.53 g, 163 mmol, 60% in mineral oil) was added in small portions over 1 min to a solution of tert-butyl prop-2-ynylcarbamate (19.5 g, 126 mmol) in N,N-dimethylformamide (300 mL) at room temperature. Formation of hydrogen bubbles was observed along with gentle warming of the resulting suspension. After 30 min at room temperature, the mixture was cooled to 0° C. Allyl bromide (13.05 mL, 151 mmol) was added dropwise. The mixture was stirred at 0° C. for 20 min and at ambient temperature for 2.5 h. The mixture was carefully quenched with water (400 mL), and extracted with ether (3×300 mL). The combined extracts were dried (MgSO4) and concentrated. Silica gel chromatography, eluting with 0-10% ethyl acetate in hexanes, gave tert-butyl allyl(prop-2-yn-1-yl)carbamate as light tan liquid (23.3 g, 95% yield). 1H NMR (400 MHz, chloroform-d) δ ppm 5.67-5.89 (1 H, m), 5.08-5.28 (2 H, m), 3.71-4.21 (4 H, m), 2.18 (1 H, t, J=2.42 Hz), 1.47 (9 H, s).

Provenance & Evidence