Methanol → 2,3,6-Trifluorobenzoic hydrazide

To 2,3,6-trifluorobenzoyl chloride (29 g, 0.15 mol) in dichloromethane (200 ml) was added methanol (30 ml) dropwise at 5° C. The solution was allowed to warm to room temperature and was stirred under nitrogen for 2 h. The solvent was removed in vacuo and the residual oil was stirred with hydrazine monohydrate (19 ml, 0.40 mol) in ethanol (120 ml) at reflux for 3 h. The solvent was removed in vacuo, and the residue was partitioned between dichloromethane (400 ml) and water (200 ml). The biphasic mixture was filtered to remove insoluble material, then the aqueous layer was washed with dichloromethane (2×300 ml). The combined organic layers were dried over magnesium sulfate, and were concentrated in vacuo to yield 2,3,6-trifluorobenzoic hydrazide as a white solid (6.0 g). Data for the title compound: 1H NMR (400 MHz, CDCl3) δ 4.18 (2H, br s), 6.93 (1H, m), 7.25 (2H, m); MS (ES+) m/e 191 [MH]+.

1. customThe solvent was removed in vacuo
2. temperatureat reflux for 3 h
3. customThe solvent was removed in vacuo
4. customthe residue was partitioned between dichloromethane (400 ml) and water (200 ml)
5. filtrationThe biphasic mixture was filtered
6. customto remove insoluble material
7. washthe aqueous layer was washed with dichloromethane (2×300 ml)
8. dry with materialThe combined organic layers were dried over magnesium sulfate
9. concentrationwere concentrated in vacuo

ORD record

ord-1b1dc2a8de1f429ab5ad1dfe5ad14dfe

Source dataset

uspto-grants-2005_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06872720B2