反应详情

Crude (S)-3-(tert-butoxycarbonyl(cyclopropylmethyl)amino)-2-(4-chlorophenyl)propanoic acid (4.6 g, 13 mmol) was dissolved into DCM (130 mL) and excess 4N HCl was added. The reaction was allowed to stir overnight, after which it was concentrated. The resulting white solid was taken up into EtOAC and filtered. The resulting solid washed with EtOAc (4×) to give pure (S)-2-(4-chlorophenyl)-3-(cyclopropylmethylamino)propanoic acid hydrochloride (3.60 g, 95%). This (S)-2-(4-chlorophenyl)-3-(cyclopropylmethylamino)propanoic acid (0.57 g, 2.24 mmol) was dissolved into 10:1 CH3CN:H2O (50 mL) and tetramethylammonium hydroxide pentahydrate (1.00 g) was added followed by Boc2O (0.73 g, 3.36 mmol). The reaction mixture was allowed to stir at room temperature overnight, and the reaction was quenched by the addition of 1N HCl. The reaction was concentrated, and the residue was diluted with EtOAc. The organics were separated, and the aqueous portion was extracted with EtOAc. The combined organics were dried with MgSO4, filtered and concentrated. The crude residue was purified by silica plug eluting Hex to 1:1 Hex/EtOAc to give (S)-3-( tert-butoxycarbonyl(cyclopropylmethyl)amino)-2-(4-chlorophenyl)propanoic acid (0.58 g, 73%) as a clear oil. (LCMS (APCI+) [M-Boc+H]+ 254.0)

1. additionwas added
2. concentrationafter which it was concentrated
3. filtrationfiltered
4. washThe resulting solid washed with EtOAc (4×)