(NE)-N-(furan-2-ylmethylidene)hydroxylamine

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

Procedure: In 3 ml of pyridine-acetone (pyridine-acetone=2:1) were dissolved 341 mg (1 mmol) of N-(furfurylidene)-(5-fluoro-5-isobutoxycarbonyl-1,2,3,4,5,6-hexahydro-2,4-dioxopyrimidine-6-yl)amine N-oxide and 133 mg (1.2 mmol) of (E)-furfuraldoxime, and the solution was stirred at room temperature for 51 hours. The reaction solution was treated in the same manner as described in Example 9 to give 188 mg of isobutyl 5-fluoro-6-[(E)-furfurylideneaminooxy]-1,2,3,4,5,6-hexahydro-2,4-dioxopyrimidine-5-carboxylate. The reaction solution was treated in the same manner

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

Procedure: In 10 ml of pyridine were dissolved 2.9 g (10 mmol) of isobutyl 5-fluoro-6-acetoxy-1,2,3,4,5,6-hexahydro-2,4-dioxopyrimidine-5-carboxylate and 2.22 g (20 mmol) of (E)-furfuraldoxime, and 1.01 g (10 mmol) of dried triethylamine was added to the solution, followed by stirring at room temperature for 21 hours. The reaction solution was concentrated under reduced pressure, and 50 ml of ethyl acetate was added to the residue. The organic layer was washed three times with 10-ml portions of water, and the solvent was dried and evaporated under reduced pressure. The residue was recrystallized twice from ethyl acetate-hexane to give 2.39 g of isobutyl 5-fluoro-6-(E)-furfurylideneaminooxy-1,2,3,4,5,6-hexahydro-2,4-dioxopyrimidine-5-carboxylate. m.p. 167°-168° C. was added to the solution The reaction solution was concentrated under reduced pressure, and 50 ml of ethyl acetate was added to the residue The organic layer was washed three times with 10-ml portions of water the solvent was dried evaporated under reduced pressure The residue was recrystallized twice from ethyl acetate-hexane

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

Procedure: In 10 ml of pyridine were dissolved 2.9 g (10 mmol) of isobutyl 5-fluoro-6-acetoxy-1,2,3,4,5,6-hexahydro-2,4-dioxopyrimidine-5-carboxylate and 2.22 g (20 mmol) of (E)-furfuraldoxime, and 1.01 g (10 mmol) of dried triethylamine was added to the solution, followed by stirring at room temperature for 21 hours. The reaction solution was concentrated under reduced pressure, and 50 ml of ethyl acetate was added to the residue. The organic layer was washed three times with 10-ml portions of water, and the solvent was dried and evaporated under reduced pressure. The residue was recrystallized twice from ethyl acetate-hexane to give 2.39 g of isobutyl 5-fluoro-6-(E)-furfurylideneaminooxy-1,2,3,4,5,6-hexahydro-2,4-dioxopyrimidine-5-carboxylate. m.p. 167°-168° C. was added to the solution The reaction solution was concentrated under reduced pressure, and 50 ml of ethyl acetate was added to the residue The organic layer was washed three times with 10-ml portions of water the solvent was dried evaporated under reduced pressure The residue was recrystallized twice from ethyl acetate-hexane

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

Procedure: In 20 ml of pyridine were dissolved 5.24 g (20 mmol) of ethyl 5-fluoro-6-acetoxy-1,2,3,4,5,6-hexahydro-2,4-dioxopyrimidine-5-carboxylate and 2.62 g (23.6 mmol) of (E)-furfuraldoxime, and 2.02 g (20 mmol) of triethylamine was added to the solution, followed by stirring at room temperature for 15 hours. The reaction solution was poured into 200 ml of ice-cooled water, and crystals precipitated were collected by filtration and washed with water. The crystals were dried under reduced pressure and recrystallized from ethanol to give 3.28 g of ethyl 5-fluoro-6-(E)-furfurylideneaminooxy-1,2,3,4,5,6-hexahydro-2,4-dioxopyrimidine-5-carboxylate. m.p. 189°-190° C. was added to the solution precipitated were collected by filtration washed with water The crystals were dried under reduced pressure recrystallized from ethanol

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

Procedure: In 3 ml of pyridine-acetone (pyridine-acetone=2:1) were dissolved 341 mg (1 mmol) of N-(furfurylidene)-(5-fluoro-5-isobutoxycarbonyl-1,2,3,4,5,6-hexahydro-2,4-dioxopyrimidine-6-yl)amine N-oxide and 133 mg (1.2 mmol) of (E)-furfuraldoxime, and the solution was stirred at room temperature for 51 hours. The reaction solution was treated in the same manner as described in Example 9 to give 188 mg of isobutyl 5-fluoro-6-[(E)-furfurylideneaminooxy]-1,2,3,4,5,6-hexahydro-2,4-dioxopyrimidine-5-carboxylate. The reaction solution was treated in the same manner

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

Procedure: In 10 ml of pyridine were dissolved 2.9 g (10 mmol) of isobutyl 5-fluoro-6-acetoxy-1,2,3,4,5,6-hexahydro-2,4-dioxopyrimidine-5-carboxylate and 2.22 g (20 mmol) of (E)-furfuraldoxime, and 1.01 g (10 mmol) of dried triethylamine was added to the solution, followed by stirring at room temperature for 21 hours. The reaction solution was concentrated under reduced pressure, and 50 ml of ethyl acetate was added to the residue. The organic layer was washed three times with 10-ml portions of water, and the solvent was dried and evaporated under reduced pressure. The residue was recrystallized twice from ethyl acetate-hexane to give 2.39 g of isobutyl 5-fluoro-6-(E)-furfurylideneaminooxy-1,2,3,4,5,6-hexahydro-2,4-dioxopyrimidine-5-carboxylate. m.p. 167°-168° C. was added to the solution The reaction solution was concentrated under reduced pressure, and 50 ml of ethyl acetate was added to the residue The organic layer was washed three times with 10-ml portions of water the solvent was dried evaporated under reduced pressure The residue was recrystallized twice from ethyl acetate-hexane

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

Procedure: In 20 ml of pyridine were dissolved 5.24 g (20 mmol) of ethyl 5-fluoro-6-acetoxy-1,2,3,4,5,6-hexahydro-2,4-dioxopyrimidine-5-carboxylate and 2.62 g (23.6 mmol) of (E)-furfuraldoxime, and 2.02 g (20 mmol) of triethylamine was added to the solution, followed by stirring at room temperature for 15 hours. The reaction solution was poured into 200 ml of ice-cooled water, and crystals precipitated were collected by filtration and washed with water. The crystals were dried under reduced pressure and recrystallized from ethanol to give 3.28 g of ethyl 5-fluoro-6-(E)-furfurylideneaminooxy-1,2,3,4,5,6-hexahydro-2,4-dioxopyrimidine-5-carboxylate. m.p. 189°-190° C. was added to the solution precipitated were collected by filtration washed with water The crystals were dried under reduced pressure recrystallized from ethanol