Ammonia → HCID 53731281, compound

Temperature

-40 °C

To a solution of 490 mg (1.51 mmol) of (2S,5R)-2-carboxy-5-hydroxy-1-p-nitrobenzyloxycarbonylpiperidine, which was prepared from the compound of Example 8-2) by a conventional method for the deprotection, in 8 ml of THF was dropwise added 0.23 ml (1.65 mmol) of triethylamine followed by 0.16 ml (1.67 mmol) of ethyl chloroformate at -30° C., and the mixture was stirred for 50 minutes at the same temperature. The mixture was cooled to -40° C., and 1.5 ml of concentrated aqueous ammonia was dropwise added. The reaction mixture was gradually warmed to room temperature and then stirred for 1 hour. The solvent was removed, and the residue was purified by silica gel column chromatography (Wakogel® C-300, elution with methanol - chloroform system). To a solution of the resulting compound in 10 ml of THF was dropwise added 0.47 ml (3.37 mmol) of triethylamine followed by 0.26 ml (3.36 mmol) of mesyl chloride, and the mixture was stirred for 2 hours at room temperature. The solvent was removed, and the residue was purified by silica gel column chromatography (Wakogel® C-300, elution with methanol - chloroform system) to give 430 mg (yield: 71%) of the title compound.

1. temperatureThe reaction mixture was gradually warmed to room temperature
2. stirringstirred for 1 hour
3. customThe solvent was removed
4. customthe residue was purified by silica gel column chromatography (Wakogel® C-300, elution with methanol - chloroform system)
5. stirringthe mixture was stirred for 2 hours at room temperature
6. customThe solvent was removed
7. customthe residue was purified by silica gel column chromatography (Wakogel® C-300, elution with methanol - chloroform system)

ORD record

ord-c9a667cd78c940198025d96dc0aa2a19

Source dataset

uspto-grants-1992_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05153188