2,6-difluorobenzohydrazide

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: This compound was prepared using the procedure described in Example 21, steps b) to f), using 3-(2-fluorophenyl)-4-hydroxy-2-furanone (cf Example 2) instead of 3-tert-butyl-4-hydroxy-2-furanone and 2,6-difluorobenzoic hydrazide instead of 2,5-difluorobenzoic hydrazide in step e). Data for the title compound: mp=163° C.; 1H NMR (360 MHz, CDCl3) δ 3.78 (3H, s), 5.52 (2H, s), 7.16 (2H, m), 7.24-7.29 (2H, m), 7.38-7.44 (1H, m), 7.60-7.65 (2H, m), 7.85 (1H, s), 9.31 (1H, s); MS (ES+) m/e 438 [MH]+. This compound was prepared

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of 3,6-dichloro-4-(1,1-dimethylethyl)pyridazine (2 g, 9.75 mmol), 2,6-difluorobenzoic acid hydrazide (2.52 g, 14.6 mmol) (WO 95/24403) and triethylamine hydrochloride (2.01 g, 14.6 mmol) in 1,4-dioxane (10 ml) was stirred and heated at reflux for 3.5 days. Upon cooling, the volatiles were removed in vacuo and the residue was triturated with dichloromethane. Any undissolved solid was removed by filtration. The residue was purified by chromatography on silica gel eluting with 0%→25% ethyl acetate in dichloromethane to give the required product (0.42 g). Data for the title compound: 1H NMR (250 MHz, CDCl3) δ1.57 (9H, s), 7.09-7.16 (2H, m), 7.51-7.63 (1H, m), 8.19 (1H, s); MS (ES30) m/e 323 (MH+. heated at reflux for 3.5 days Upon cooling the volatiles were removed in vacuo the residue was triturated with dichloromethane Any undissolved solid was removed by filtration The residue was purified by chromatography on silica gel eluting with 0%→25% ethyl acetate in dichloromethane

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: This compound was prepared using the procedure described in Example 21, steps b) to f), using 3-(2-fluorophenyl)-4-hydroxy-2-furanone (cf Example 2) instead of 3-tert-butyl-4-hydroxy-2-furanone and 2,6-difluorobenzoic hydrazide instead of 2,5-difluorobenzoic hydrazide in step e). Data for the title compound: mp=163° C.; 1H NMR (360 MHz, CDCl3) δ 3.78 (3H, s), 5.52 (2H, s), 7.16 (2H, m), 7.24-7.29 (2H, m), 7.38-7.44 (1H, m), 7.60-7.65 (2H, m), 7.85 (1H, s), 9.31 (1H, s); MS (ES+) m/e 438 [MH]+. This compound was prepared