Acrolein → HCID 18538669, compound

To a solution of 4-benzylpiperidine (3.51 g, 20.0 mmol) and DBU (0.030 ml, 0.20 mmol) in THF (40 ml) was dropwise added a solution of acrolein (90%, 1.485 ml, 20.0 mmol) in THF (10 ml) at −20° C. with stirring over a period of 10 minutes. The mixture was stirred for 1 hour while the temperature of the mixture is elevated from −20° C. to −10° C. To the mixture were added 3-amino-5-methyl isoxazole (1.96 g, 20.0 mmol) and sodium triacetoxyborohydride (8.48 g, 40.0 mmol), successively, at −10° C. The mixture was stirred for 15 hours while the temperature of the mixture is elevated to −10° C. To the mixture was added aqueous solution of 1N-sodium hydroxide (120 ml) under ice cooling, and the mixture was stirred for 30 minutes and extracted with diethyl ether (60 ml×3). The organic layer was dried over magnesium sulfate and concentrated under reduced pressure. The concentrate was subjected to column chromatography (silica gel 100 g, ethyl acetate/methanol=1/0 to 75/25), and the desired fraction was concentrated under reduced pressure to give the titled compound (2.30 g, 7.34 mmol) as white crystals. Yield 37%.

1. stirringThe mixture was stirred for 1 hour while the temperature of the mixture
2. customis elevated from −20° C. to −10° C
3. customat −10° C
4. stirringThe mixture was stirred for 15 hours while the temperature of the mixture
5. customis elevated to −10° C
6. stirringthe mixture was stirred for 30 minutes
7. extractionextracted with diethyl ether (60 ml×3)
8. dry with materialThe organic layer was dried over magnesium sulfate
9. concentrationconcentrated under reduced pressure
10. concentrationthe desired fraction was concentrated under reduced pressure

ORD record

ord-f864b73809b64e2e874e2f7c416b94cc

Source dataset

uspto-grants-2008_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07348324B2