Methyl iodide → (2E)-5-(N-(tert-butoxycarbonyl)-N-methylamino)-5-methylhex-2-enoic acid

Participants

Reaction Conditions

Reaction Steps

(2E)-5-(tert-Butyloxycarbonylamino)-5-methylhex-2-enoic acid (5.00 g; 20.6 mmol) was dissolved in tetrahydrofuran (70 ml). Methyl iodide (10.3 ml; 164 mmol) was added and the solution was cooled to 0° C. Sodium hydride (60% in oil) (2.07 g; 61.6 mmol) was added in portions and the solution was stirred at room temperature for four days. Ethyl acetate (70 ml) and water (60 ml) were added dropwise and the solvent was removed in vacuo. The crude product was dissolved in water (40 ml) and diethyl ether (40 ml). The organic phase was washed with a saturated aqueous solution of sodium hydrogencarbonate (30 ml). The aqueous phases were mixed and 5% aqueous citric acid was added to pH 3. The aqueous phase was extracted with ethyl acetate (4×50 ml). The combined organic extracts were washed with water (2×40 ml), an aqueous solution of sodium thiosulfate (5%; 40 ml), water (40 ml), dried over MgSO4 and the solvent was removed in vacuo. The residue was dissolved in ethyl acetate (45 ml) and washed with an aqueous solution of sodium hydrogensulfate (10%; 3×30 ml), dried over magnesium sulfate and concentrated in vacuo to give 4.00 g of (2E)-5-(N-(tert-butoxycarbonyl)-N-methylamino)-5-methylhex-2-enoic acid.

Provenance & Evidence