反应详情

A round-bottomed flask was charged with Boc-D-tert-leucine (2.5 g, 10.8 mmol), HOBT (4.2 g, 24.9 mmol), EDC (4.77 g, 24.9 mmol) and piperidine-4-carbonitrile (2.98 g, 27.0 mmol). Then added DMF (50 mL) followed by N,N-diisopropylethylamine (10.7 ml, 61.6 mmol). The yellow reaction mixture was stirred at room temperature overnight then quenched with 10% citric acid and extracted with EtOAc (2×). The combined organic layers were washed twice with 10% citric acid, twice with sat'd LiCl and once with brine then dried over MgSO4, filtered and concentrated to give 3.4 g (97%) of [(R)-1-(4-cyano-piperidine-1-carbonyl)-2,2-dimethyl-propyl]-carbamic acid tert-butyl ester as a beige foamy solid.

1. customthen quenched with 10% citric acid
2. extractionextracted with EtOAc (2×)
3. washThe combined organic layers were washed twice with 10% citric acid, twice with sat'd LiCl and once with brine
4. dry with materialthen dried over MgSO4
5. filtrationfiltered
6. concentrationconcentrated