反应详情

In a 500 ml round bottom flask 6-chloronicotinaldehyde (5 g, 35.3 mmol, Eq: 1.00) was suspended in DCM (350 ml). 1-Methylpiperazine (4.42 g, 4.9 ml, 44.2 mmol, Eq: 1.25) was added, followed by acetic acid (4.24 g, 4.04 ml, 70.6 mmol, eq: 2.0). Sodium triacetoxyborohydride (11.2 g, 53.0 mmol, Eq: 1.5) was added by portions over several minutes. The reaction stirred at room temperature for three hours. Water and DCM were added and the layers were separated. The aqueous layer was brought to pH 10 with 1M NaOH. The aqueous layer was extracted three times with DCM. The combined extract was dried over Na2SO4 and concentrated in vacuo to give 1-(6-chloro-pyridin-3-ylmethyl)-4-methyl-piperazine (6.8 g, 85%) LC/MS-ESI observed [M+H]+ 226. The crude material was used “as is” in the next reaction.

1. customthe layers were separated
2. extractionThe aqueous layer was extracted three times with DCM
3. extractionThe combined extract
4. dry with materialwas dried over Na2SO4
5. concentrationconcentrated in vacuo