Synthesis
General procedure for the synthesis of methyl 2-(triphenylphosphoranylidene)propionate from methyl 2-bromopropionate and triphenylphosphine: first, 5 g (19.06 mmol) of triphenylphosphine was dissolved in 15 ml of toluene. Subsequently, an aqueous solution prepared by dissolving 0.32 g (1.90 mmol) of potassium iodide in 15 ml of distilled water mixed with 3.2 ml (28.6 mmol) of methyl 2-bromopropionate was added to this solution. The reaction mixture was stirred continuously at 70°C for 20 hours. After completion of the reaction, the mixture was cooled to room temperature and alkalized by adjusting the pH to 9 with 10N aqueous sodium hydroxide solution, followed by extraction with dichloromethane. The organic layer was collected and dried with anhydrous sodium sulfate, followed by filtration under reduced pressure and distillation under reduced pressure. The resulting solid was washed with hexane and again subjected to filtration under reduced pressure and drying under reduced pressure to give 6.0 g (yield: 91%) of the target product methyl 2-(triphenylphosphoranylidene)propionate.
References
[1] Patent: KR2015/77974, 2015, A. Location in patent: Paragraph 0033-0034; 0053-0055
[2] Organic and Biomolecular Chemistry, 2017, vol. 15, # 34, p. 7102 - 7105
[3] Helvetica Chimica Acta, 1979, vol. 62, p. 1025 - 1039
[4] Tetrahedron Letters, 1984, vol. 25, # 51, p. 5881 - 5884
[5] Angewandte Chemie - International Edition, 2012, vol. 51, # 38, p. 9587 - 9591
