反应详情

A stirring solution of (1R,2S,5R)-2-((S)-3-(benzyloxycarbonylamino)-2-oxopyrrolidin-1-yl)-5-(tert-butoxycarbonylamino)cyclohexanecarboxylic acid (38 g, 0.0799 mol; see Example 1, Step 4) in dichloromethane (400 mL) was charged with trifluoroacetic acid (100 mL) at 0° C. The reaction was stirred for 2 h at room temperature and concentrated in vacuo. The residue was dissolved in dichloromethane (100 ml) and the resultant solution was added dropwise to diethyl ether (1500 ml) with stirring. The solid formed was collected with filtration and washed with diethyl ether (3×50 ml). The white solid was dried in vacuo to give (1R,2S,5R)-5-amino-2-((S)-3-(benzyloxycarbonylamino)-2-oxopyrrolidin-1-yl)cyclohexanecarboxylic acid as its TFA salt (35.5 g, 86%). The compound was used to next step without further purification. LC/MS found [M+H]+=376.

1. concentrationconcentrated in vacuo
2. dissolutionThe residue was dissolved in dichloromethane (100 ml)
3. additionthe resultant solution was added dropwise to diethyl ether (1500 ml)
4. stirringwith stirring
5. customThe solid formed
6. filtrationwas collected with filtration
7. washwashed with diethyl ether (3×50 ml)
8. customThe white solid was dried in vacuo