p-Toluenesulfonic acid → HCID 53664316, compound

Participants

Reaction Steps

To a stirred suspension of 4-nitrobenzyltriphenylphosphonium chloride (10.02 g, 23.1 mmol) in CH2Cl2 (100 mL) was added 4-methylmorpholine (2.54 mL, 23.1 mmol) was added. When all the solid had dissolved, Boc-HphH (4.04 g, 15.4 mmol) was added. After 24 hrs., the reaction mixture was diluted with CH2Cl2 (200 mL), and filtered. The filtrate was washed with 1M HCl (200 mL) saturated aqueous sodium bicarbonate (200 mL); dried over MgSO4, filtered and concentrated under reduced pressure, giving 4.00 g of crude intermediate, a portion of which was purified by chromatography (gradient elution: 10-30% ethyl acetate/hexane) to permit NMR analysis of the intermediate, (S)-t-butoxycarbonyl-3-amino-1-(4-nitrophenyl)-5-phenyl-1-pentene. TLC: (30% EtOAc /hexane) Rf =0.49. To a solution of this material (2.76 g, 7.2 mmol) in Et2O (25 mL), was added a solution of anhydrous p-toluenesulfonic acid (2.76 g, 16.0 mmol) in Et2O (10 mL). The reaction was left to stir 16 hrs, filtered; washed solid with Et2O (25 mL), and dried in vacuo, giving 2 g (61%) of (S)-3-amino-1-(4-nitrophenyl)-5-phenyl-1-pentene as a single spot on TLC: (Rf=0.49, 10% MeOH/CH2Cl2).

Provenance & Evidence