Methanol → Ethyl 4-hydroxypiperidine-1-carboxylate

To a suspension of 68.5 parts of ethyl 4-oxo-1-piperidinecarboxylate in 240 parts of methanol was added portionwise 3.8 parts of sodium borohydride at a temperature between 20°-30° C. (the reaction mixture was cooled if necessary in a water-bath). After the addition was complete, the whole was stirred for 30 minutes. The reaction mixture was then poured into a mixture of 53.5 parts of ammonium chloride and 400 parts of water. The methanol was evaporated. The product was extracted with trichloromethane. The extract was dried and evaporated. The oily residue was distilled in vacuo, yielding 60 parts of oily ethyl 4-hydroxy-1-piperidinecarboxylate; bp. 140° C. at 1.4 mm. pressure; nD20 : 1.4796; d2020 : 1.1166 (3).

1. temperaturewas cooled if necessary in a water-bath)
2. additionAfter the addition
3. customThe methanol was evaporated
4. extractionThe product was extracted with trichloromethane
5. customThe extract was dried
6. customevaporated
7. distillationThe oily residue was distilled in vacuo

ORD record

ord-23412feb2b8e497ab6c1a34cc32e8742

Source dataset

uspto-grants-1989_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04839374