Benzenesulfonic acid, 4-methyl-, compd. with pyridine (1:1) → 2-(1-Boc-piperidin-4-ylmethylamino)-5-chloro-N-(5-chloropyridin-2-yl)benzamide

Temperatur

70 °C

To a solution of 1-Boc-piperidine-4-carboxaldehyde (3.5 g, 14 mmol) and 2-amino-5-chloro-N-(5-chloropyridin-2-yl)benzamide (3.9 g, 14 mmol) in benzene (250 mL), a catalytic amount of pyridinium p-toluenesulfonate (0.35 g, 1.4 mmol) was added, followed by 4A molecular sieves. The reaction mixture was heated at reflux for 48 h with azeotropic removal of water. The mixture was subsequently filtered through a pad of diatomaceous earth, washing well with ethyl acetate. The filtrate was concentrated in vacuo to a residue that was taken up in acetic acid (100 mL) and treated with borane-trimethylamine complex (3 g, 42 mmol). The mixture was heated at 70° C. for 24 h; then it was diluted with 2 N NaOH and extracted with dichloromethane The water layer was neutralized with solid sodium bicarbonate, and further extracted with dichloromethane The combined organic extracts were dried with MgSO4, filtered, and concentrated in vacuo to a solid residue (8 g, >100%) which was identified as the desired product and taken on directly to the next step without further purification.

1. temperatureThe reaction mixture was heated
2. filtrationThe mixture was subsequently filtered through a pad of diatomaceous earth
3. washwashing well with ethyl acetate
4. concentrationThe filtrate was concentrated in vacuo to a residue that
5. extractionextracted with dichloromethane The water layer
6. extractionfurther extracted with dichloromethane The combined organic extracts
7. dry with materialwere dried with MgSO4
8. filtrationfiltered
9. concentrationconcentrated in vacuo to a solid residue (8 g, >100%) which
10. customwithout further purification

ORD-Eintrag

ord-b1ba55f40d0a4e63969551a15c006268

Quelldatensatz

uspto-grants-2003_10

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US06635657B1