Ammonia → 6-(Diphenylphosphanyl)pyridin-2-amine

Temperature

-78 °C

At −78° C., 200 ml of ammonia were condensed in and 5.00 g of sodium (216.8 mmol) were dissolved therein within 5 min. The resulting dark blue solution was admixed with 11.70 g of triphenylphosphine (108.4 mmol) in portions, stirred at −78° C. for approx. 2 h and then admixed with 15.00 g (86.7 mmol) of 6-bromo-2-aminopyridine from example 14.1. After 250 ml of toluene had been added, the cold bath was removed and the ammonia evaporated off overnight. The residue was hydrolyzed with 150 ml of dist. H2O and admixed with 150 ml of saturated NaCl solution, the resulting phases were separated and the aqueous phase was extracted once with 200 ml of toluene. The combined organic phases were dried over MgSO4 and concentrated under reduced pressure. The product was purified by column chromatography (first with dichloromethane to remove diphenylphosphine, then with 9:1 dichloromethane/ethyl acetate). Resulting mixed fractions were purified by sublimation at 180° C. and 10−2 mbar. 14.26 g (51.2 mmol, 59%) of 6-(diphenylphosphino)-2-aminopyridine were obtained as a white solid.

1. customAt −78° C.
2. dissolutionwere dissolved
3. customthe cold bath was removed
4. customthe ammonia evaporated off overnight
5. customthe resulting phases were separated
6. extractionthe aqueous phase was extracted once with 200 ml of toluene
7. dry with materialThe combined organic phases were dried over MgSO4
8. concentrationconcentrated under reduced pressure
9. customThe product was purified by column chromatography (first with dichloromethane
10. customto remove diphenylphosphine
11. customResulting
12. additionmixed fractions
13. customwere purified by sublimation at 180° C.

ORD record

ord-c677c89a7d2847948a1b35e677f06ed3

Source dataset

uspto-grants-2006_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07049473B2