Diethyl Ether → HCID 20672430, compound

A mixture of 1.29 g (5.0 mmol) of 2-(S)-((t-butoxycarbonyl) piperidin-4-yl)propanoic acid (from EXAMPLE 30, Step C) and 0.70 mL (5.0 mmol) of TEA in 30 mL of THF at 0° C. was treated with 0.43 mL (5.0 mmol) of ethyl chloroformate and the resulting mixture was stirred cold for 30 min. The solids were filtered. The filtrate was added to a cooled (0° C.) mixture of 0.50 g (13.0 mmol) of NaBH4 in 10 mL of H2O, maintaining the internal temperature at less than 10° C. The resulting mixture was warmed to rt and stirred for 1 h. The reaction was layered with 75 mL of ether and quenched with 25 mL of 1.0 N HCl. The layers were separated. The organic layer was washed with 25 mL of 1.0 N NaOH, 25 mL of sat'd NaCl, dried over MgSO4 and concentrated to afforded 1.90 g (88%) of the title compound: 1H NMR (500 MHz) δ 0.90 (d, J=6.5, 3H), 1.17-1.66 (5H), 1.45 (s, 9H), 2.65 (br s, 2H), 3.56 (dABq, J=5.5, 10.5), 4.13 (br s, 2H1).

1. filtrationThe solids were filtered
2. additionThe filtrate was added to
3. temperaturea cooled
4. temperaturemaintaining the internal temperature at less than 10° C
5. stirringstirred for 1 h
6. customquenched with 25 mL of 1.0 N HCl
7. customThe layers were separated
8. washThe organic layer was washed with 25 mL of 1.0 N NaOH, 25 mL of sat'd NaCl
9. dry with materialdried over MgSO4
10. concentrationconcentrated

ORD record

ord-df70f2410d27439e8906e1ec2adc70dc

Source dataset

uspto-grants-2001_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06265434B1