Pyridine-2-carbonitrile → Pyridine-2-carbothioamide

Adapting the general method of Taylor, a mixture of 2-cyanopyridine (7.28 g, 7.0 mmol) and thioacetamide (10.52 g, 14.0 mmol) was treated with 60 ml of HCl-saturated DMF, and the solution was stirred vigorously in an open flask on an oil bath set initially at 80° C. (the temperature gradually rising to 95° C. over the coarse of the reaction). Taylor, E. C. et al., J. Am. Chem. Soc. 1960, 82, 2656-2657. After 80 minutes (TLC monitoring), the resulting orange suspension was cooled, neutralized with con. NaOH/ice, and extracted with EtOAc. The extract was washed with water (3×) and then concentrated to a light brown solid which was triturated with warm water and collected. The dried product was passed over a silica gel column eluting with EtOAc:hexanes (2:1) to give, after removal of most of the solvent and dilution with hexanes, a yellow crystalline solid (6.36 g, 66%), mp 136-137° C.; lit mp 137° C.

1. customset initially at 80° C.
2. customgradually rising to 95° C.
3. customcoarse of the reaction)
4. temperaturethe resulting orange suspension was cooled
5. extractionNaOH/ice, and extracted with EtOAc
6. washThe extract was washed with water (3×)
7. concentrationconcentrated to a light brown solid which
8. customwas triturated with warm water
9. customcollected
10. washeluting with EtOAc:hexanes (2:1)
11. customto give
12. customafter removal of most of the solvent and dilution with hexanes

ORD-Eintrag

ord-51590acb9e4545c5ba6600064ef91b6d

Quelldatensatz

uspto-grants-2010_06

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US07745456B2