The general procedure for the synthesis of methyl 2-cyano-2-methylpropionate from methyl cyanoacetate and iodomethane is as follows:
1. In a dry reaction flask, methyl cyanoacetate (15 mL) and iodomethane (200 g) were added with potassium carbonate as base and acetone as solvent.
2. The reaction mixture was heated to reflux with continuous stirring for 4 days.
3. Upon completion of the reaction, insoluble potassium carbonate was removed by filtration.
4. The acetone in the filtrate was removed by distillation to obtain the crude product.
5. The crude product was purified by vacuum distillation (pressure: 16 mmHg, temperature: 76°C) to give methyl 2-cyano-2-methylpropionate (19.5 g, 73% yield).
Product characterization data:
1H NMR (270 MHz, CDCl3) δ: 1.62 (s, 6H), 3.83 (s, 3H).
13C NMR (67.5 MHz, CDCl3) δ: 24.6, 38.4, 121.0, 170.0.
[1] Patent: US5866592, 1999, A
[2] Patent: EP2533783, 2015, B1. Location in patent: Paragraph 0551-0552
[3] Acta Chemica Scandinavica (1947-1973), 1968, vol. 22, # 8, p. 2453 - 2461
[4] Phosphorus and Sulfur and the Related Elements, 1987, vol. 32, p. 153 - 162
[5] Patent: WO2013/134660, 2013, A1. Location in patent: Paragraph 0428
