1-amino-3-(3,5-difluorophenyl)urea

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

Procedure: To a solid 100 mg of O-phenyl 3,5-difluorophenylcarbamate 0.7 mL of hydrazine monohydrate was added. After stirring for 3 h at room temperature a white solid is collected by filtration, washed with water and ether. Removal of traces of the solvents in vacuo gives 4-(3,5-difluorophenyl)-semicarbazide: m.p. 177°-179° C. is collected by filtration washed with water and ether Removal of traces of the solvents in vacuo

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

Procedure: To 50 mg of 2-acetylnicotinic acid are added 56 mg of 4-(3,5-difluorophenyl)semicarbazide and 1 mL of methanol. After a minute of stirring the product begins precipitating from the solution. After stirring overnight (15 h) the stir vane is removed and rinsed with 0.2 mL of methanol. The reaction mixture is centrifuged and the supernatant solution removed. In the same way the solid is rinsed with methanol (3×0.5 mL) and ether (1×0.5 mL). The solid is dried in vacuo with heating to give 2-acetylnicotinic acid 4-(3,5-difluorophenyl)semicarbazone (also known as 2-[methyl-{[(3,5-difluorophenylamino)carbonyl]hydrazono}methyl]-3-pyridine-carboxylic acid), m.p. 186° (compound 31, Table A). begins precipitating from the solution After stirring overnight (15 h) the stir vane is removed rinsed with 0.2 mL of methanol the supernatant solution removed In the same way the solid is rinsed with methanol (3×0.5 mL) and ether (1×0.5 mL) The solid is dried in vacuo with heating

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

Procedure: 3 g of 6-fluoro-2-acetyl benzoic acid and 3 g of 4-(3,5-difluorophenyl)-semicarbazide are mixed in 20 ml of methanol and heated until clear. The solution is then stirred at R.T. for 24 hr. A white solid forms which is filtered and dried in vacuum at 60° to yield the title product m.p. 227° (decomp.). The corresponding sodium salt is made by reaction of the free acid with 25% sodium methoxylate/methanol. heated until clear A white solid forms which is filtered dried in vacuum at 60°

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

Procedure: 3 g of 6-fluoro-2-acetyl benzoic acid and 3 g of 4-(3,5-difluorophenyl)semicarbazide are mixed in 20 ml of methanol and heated until clear. The solution is then stirred at R. T. for 24 hr. A white solid forms which is filtered and dried in vacuum at 60° to yield the title product m.p. 227° (decomp.). The corresponding sodium salt is made by reaction of the free acid with 25% sodium methoxylate/methanol. heated until clear A white solid forms which is filtered dried in vacuum at 60°

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

Procedure: 3 g of 6-fluoro-2-acetyl benzoic acid and 3 g of 4-(3,5-difluorophenyl)-semicarbazide are mixed in 20 ml of methanol and heated until clear. The solution is then stirred at R.T. for 24 hr. A white solid forms which is filtered and dried in vacuum at 60° to yield the title product m.p. 227° (decomp.). The corresponding sodium salt is made by reaction of the free acid with 25% sodium methoxylate/methanol. heated until clear A white solid forms which is filtered dried in vacuum at 60°

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

Procedure: 3 g of 6-fluoro-2-acetyl benzoic acid and 3 g of 4-(3,5-difluorophenyl)semicarbazide are mixed in 20 ml of methanol and heated until clear. The solution is then stirred at R.T. for 24 hr. A white solid forms which is filtered and dried in vacuum at 60° to yield the title product m.p. 227° (decomp.). The corresponding sodium salt is made by reaction of the free acid with 25% sodium methoxylate/methanol. heated until clear A white solid forms which is filtered dried in vacuum at 60°

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

Procedure: 3 g of 6-fluoro-2-acetyl benzoic acid and 3 g of 4-(3,5-difluorophenyl)semicarbazide are mixed in 20 ml of methanol and heated until clear. The solution is then stirred at R.T. for 24 hr. A white solid forms which is filtered and dried in vacuum at 60° to yield the title product m.p. 227° (decomp.). The corresponding sodium salt is made by reaction of the free acid with 25% sodium methoxylate/methanol. heated until clear A white solid forms which is filtered dried in vacuum at 60°