反应详情

A mixture of 2-cyano-3-(ethylthio)pyridine (613 mg, 3.73 mmol) and concentrated HCl (0.93 mL, 11.2 mmol) in degassed ethanol (18 mL) was hydrogenated over 10% palladium on carbon (184 mg) at 60 psi overnight. Additional 10% palladium on carbon (180 mg) and conc. HCl (1 mL) were added to the reaction and hydrogenation was resumed at 61 psi overnight. The reaction mixture was filtered through Celite and washed with methanol. The filtrate was concentrated at reduced pressure to an orange solid which was taken up in methanol (12 mL). 10% Palladium on carbon (300 mg) and concentrated HCl (2.4 mL of a 6 M aqueous solution) were added and the mixture was hydrogenated at 57 psi for 3 days. The reaction mixture was again filtered through Celite, and the filter cake was washed with ethanol. The product was concentrated to a yellow-orange oil, which was taken up in methanol and treated with 1.0 M HCl in ether. The solvent was removed is vacuo to afford the title compound as an orange solid:

1. customwas resumed at 61 psi overnight
2. filtrationThe reaction mixture was filtered through Celite
3. washwashed with methanol
4. concentrationThe filtrate was concentrated at reduced pressure to an orange solid which
5. addition10% Palladium on carbon (300 mg) and concentrated HCl (2.4 mL of a 6 M aqueous solution) were added
6. filtrationThe reaction mixture was again filtered through Celite
7. washthe filter cake was washed with ethanol
8. concentrationThe product was concentrated to a yellow-orange oil, which
9. additiontreated with 1.0 M HCl in ether
10. customThe solvent was removed