Hydrazine → 3-(4-bromo-2-fluorophenyl)-4H-1,2,4-triazole

Temperature

97.5 °C

Hydrazine (0.14 mL, 4.4 mmol) was added to a solution of (E)-4-bromo-N-((dimethylamino)methylene)-2-fluorobenzamide (1.105 g, 4.046 mmol) in acetic acid (11 mL). The resulting white suspension was heated to 95-100° C. The resulting solution was stirred at 95-100° C. for 2 hours. The reaction mixture was cooled to ambient temperature and the acetic acid was azeotropically removed in vacuo with multiple additions of heptane. Heptane (10 mL) was added to the residue. The resulting suspension was cooled to 0-5° C. and stirred for 1 hour. The solids were collected by vacuum filtration, rinsed with excess heptane, and dried to afford 5-(4-bromo-2-fluorophenyl)-1H-1,2,4-triazole (1.116 g, 114%) as an off-white solid which was carried on without further purification.

1. temperatureThe reaction mixture was cooled to ambient temperature
2. customthe acetic acid was azeotropically removed in vacuo with multiple additions of heptane
3. additionHeptane (10 mL) was added to the residue
4. temperatureThe resulting suspension was cooled to 0-5° C.
5. stirringstirred for 1 hour
6. filtrationThe solids were collected by vacuum filtration
7. washrinsed with excess heptane
8. customdried

ORD record

ord-db5d27b0f18b4f64bf1215309455f401

Source dataset

uspto-grants-2014_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08865726B2