Acetic Acid → Ethyl 1-methylpiperidine-4-carboxylate

Temperature

0 °C

Piperidine-4-carboxylic acid ethyl ester (78 g) was dissolved in MeOH (1.2 L) at RT then formaldehyde (37%, 90 ml) and acetic acid (42 ml) were added and stirred for 2 h. The mixture was cooled to 0° C., NaCNBH3 (70 g) was added, and the mix was stirred for 20 min at 0° C., then overnight at RT. The mixture was cooled to 0° C. then quenched with 6N NaOH. The mixture was concentrated in vacuo to an aqueous layer, which was extracted with EtOAc (4×), brine-washed, dried over Na2SO4, and concentrated in vacuo to provide 1-methylpiperidine-4-carboxylic acid ethyl ester.

1. stirringthe mix was stirred for 20 min at 0° C.
2. customovernight
3. customat RT
4. temperatureThe mixture was cooled to 0° C.
5. customthen quenched with 6N NaOH
6. concentrationThe mixture was concentrated in vacuo to an aqueous layer, which
7. extractionwas extracted with EtOAc (4×), brine-
8. washwashed
9. dry with materialdried over Na2SO4
10. concentrationconcentrated in vacuo

ORD record

ord-ae163eb1c1314ee4bece2682b9f8d38c

Source dataset

uspto-grants-2014_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08642624B2