1,1-bis(2,2-dimethylpropoxy)-N,N-dimethylmethanamine

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

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

Procedure: A solution of 4-phenylpiperazine (0.162 g, 0.001 mol) and dimethylformamide dineopentyl acetal (0.346 g, 0.0015 mol) in anhydrous chloroform (5 mL) was refluxed for 10 hours. The solvent and excess reagent were removed (100° C./1 mm) to give the product in quantitative yield. The solvent and excess reagent were removed (100° C./1 mm) to give the product in quantitative yield

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

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

Procedure: In 4 ml of toluene was suspended 200 mg of ethyl 2-[2-(2,4-difluorophenylamino)-5-fluoro-6-hydroxynicotinoyl]acetate, and 200 mg of N,N-dimethylformamide dineopentylacetal was added thereto, after which the resulting mixture was subjected to reaction at room temperature for 4 hours. The crystals thus deposited were collected by filtration, and to the crystals were added 5 ml of ethanol and 5 ml of water, after which the pH thereof was adjusted to 1.0 with 2N hydrochloric acid. Thereafter, the crystals thus deposited were collected by filtration to obtain 155 mg (yield 75.4%) of ethyl 1-(2,4-difluorophenyl)-6-fluoro-1,4-dihydro-7-hydroxy-4-oxo-1,8-naphthyridine-3-carboxylate having a melting point of 244°-248° C. The physical properties of this compound were identical with those of the compound obtained in Example 40. was added after which the resulting mixture was subjected to reaction at room temperature for 4 hours The crystals thus deposited were collected by filtration to the crystals were added 5 ml of ethanol and 5 ml of water Thereafter, the crystals thus deposited were collected by filtration

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

Procedure: In 4 ml of toluene was suspended 200 mg of ethyl 2-[2-(2,4-difluorophenylamino)-5-fluoro-6-hydroxynicotinoyl]acetate, and 200 mg of N,N-dimethylformamide dineopentylacetal was added thereto, after which the resulting mixture was subjected to reaction at room temperature for 4 hours. The crystals thus deposited were collected by filtration, and to the crystals were added 5 ml of ethanol and 5 ml of water, after which the pH thereof was adjusted to 1.0 with 2N hydrochloric acid. Thereafter, the crystals thus deposited were collected by filtration to obtain 155 mg (yield 75.4%) of ethyl 1-(2,4-difluorophenyl)-6-fluoro-1,4-dihydro-7-hydroxy-4-oxo-1,8-naphthyridine-3-carboxylate having a melting point of 244°-248° C. The physical properties of this compound were identical with those of the compound obtained in Example 40. was added after which the resulting mixture was subjected to reaction at room temperature for 4 hours The crystals thus deposited were collected by filtration to the crystals were added 5 ml of ethanol and 5 ml of water Thereafter, the crystals thus deposited were collected by filtration