Sodium Hydroxide → 5-Hydrazinyl-2-(trifluoromethyl)pyridine

Temperatur

0 °C

1-(6-(Trifluoromethyl)pyridin-3-yl)hydrazine was prepared as follows: A 250-mL round bottomed flask containing a solution of 6-(trifluoromethyl)pyridin-3-amine (5.76 g, 35.5 mmol) in 50 mL of 4 N HCl was cooled to 0° C. in an ice bath and a solution of sodium nitrite (2.57 g, 37.3 mmol) in 5 mL of water was added dropwise. The reaction mixture was stirred at 0° C. for 30 min and added to a solution of tin(II) chloride dihydrate (16.8 g, 74.6 mmol) in 60 mL of 4 N HCl at 80° C. The reaction mixture was stirred at 80° C. for 3 h, cooled to room temperature, and made basic by the addition of 10 N NaOH. The aqueous phase was extracted with EtOAc (4×). The combined organic extracts were concentrated and the crude material was absorbed onto silica gel. Purification by flash column chromatography on silica gel (10% to 100% EtOAc in hexanes) gave 1-(6-(trifluoromethyl)pyridin-3-yl)hydrazine.

1. custom1-(6-(Trifluoromethyl)pyridin-3-yl)hydrazine was prepared
2. stirringThe reaction mixture was stirred at 80° C. for 3 h
3. temperaturecooled to room temperature
4. extractionThe aqueous phase was extracted with EtOAc (4×)
5. concentrationThe combined organic extracts were concentrated
6. customthe crude material was absorbed onto silica gel
7. customPurification by flash column chromatography on silica gel (10% to 100% EtOAc in hexanes)

ORD-Eintrag

ord-db95a3124751491da5cca82fb828081b

Quelldatensatz

uspto-grants-2012_12

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08334317B2