Dimethyl Sulfate → 2,2-Dimethoxy-1-methylpyrrolidine

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To a mixture containing 10 mL (10.28 g, 104 mmol) of N-methyl-2-pyrrolidinone and 10 mL (13.25 g, 105 mmol) of dimethyl sulfate was stirred and heated at 90° C. for 1.5 h, then allowed to cool to room temperature. A solution containing 25 mL of 25% methanolic sodium methoxide and 72 mL of methanol was added at −10° C. under Ar over a period of 1 h. The precipitated solid was filtered and the solvent was concentrated under diminished pressure. The residue was dissolved in 100 mL of ether and stirred for 1 h, then the precipitated solid was filtered. The solid was washed with two 10-mL portions of ether. After concentration under diminished pressure, the residue was distilled in vacuo to give 2,2-dimethoxy-1-methylpyrrolidine as a yellow liquid: yield 4.42 g (29%); 1H NMR (CDCl3) δ 1.62-1.74 (m, 2H), 1.83 (t, 2H, J=7.8 Hz), 2.28 (s, 3H), 2.78 (t, 2H, J=6.6 Hz), 3.15 (s, 3H).

Herkunft & Nachweise