Hydrazine hydrate (1:1) → 5-Fluoro-2-hydrazinylpyridine

Temperature

200 °C

2-chloro-5-fluoropyridine (5.00 g, 38.01 mmol) was combined with hydrazine monohydrate (15 mL, 303.0 mmol) in a Teflon® lined reactor. The reaction was purged with argon gas and sealed, then heated to 200° C. overnight. Following overnight heating, the reaction mixture was evaporated to solids under reduced pressure, and then dissolved in water containing NaHCO3. The mixture was transferred to a reparatory funnel, and extracted 4 times with EtOAc. The combined organic extracts were dried over Na2SO4, filtered and concentrated to residue under reduced pressure, followed by purification by flash column chromatography eluting with 5% MeOH 0.5% NH4OH in DCM to give the desired 5-fluoro-2-hydrazinylpyridine (1.50 g, 31% yield). MS APCI (+) m/z 128.0 (M+1) detected.

1. customThe reaction was purged with argon gas
2. customsealed
3. temperatureheating
4. customthe reaction mixture was evaporated to solids under reduced pressure
5. dissolutiondissolved in water
6. additioncontaining NaHCO3
7. customThe mixture was transferred to a reparatory funnel
8. extractionextracted 4 times with EtOAc
9. dry with materialThe combined organic extracts were dried over Na2SO4
10. filtrationfiltered
11. concentrationconcentrated to residue under reduced pressure
12. customfollowed by purification by flash column chromatography
13. washeluting with 5% MeOH 0.5% NH4OH in DCM

ORD record

ord-b0b8c9cbc3e542278028e438e82fdebc

Source dataset

uspto-grants-2013_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08575145B2