N'-methylacetohydrazide

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:120.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of methyl 8-[(4-methoxybenzyl)oxy]-5-vinyl-[1,6]-naphthyridine-7-carboxylate (0.26 g, 0.73 mmol), paraformaldehyde (96 mg), and 1-acetyl-2-methylhydrazine (0.22 g, 2.45 mmol; J. Org. Chem. 1972, 37, 3608) in toluene (15 mL) was heated in an oil bath at 120° C. for 1.5 hour. The resulting mixture was concentrated under vacuum. The residue was subjected to column chromatography on silica gel eluting first with a gradient of 0-5% methanol in ethyl acetate. Collection and concentration of appropriate fractions provided the title acetylpyrazolidine. The resulting mixture was concentrated under vacuum Collection and concentration of appropriate fractions

Conditions: temp:120.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of methyl 8-[(4-methoxybenzyl)oxy]-5-vinyl-[1,6]-naphthyridine-7-carboxylate (0.26 g, 0.73 mmol), paraformaldehyde (96 mg), and 1-acetyl-2-methylhydrazine (0.22 g, 2.45 mmol; J. Org. Chem. 1972, 37, 3608) in toluene (15 mL) was heated in an oil bath at 120° C. for 1.5 hour. The resulting mixture was concentrated under vacuum. The residue was subjected to column chromatography on silica gel eluting first with a gradient of 0-5% methanol in ethyl acetate. Collection and concentration of appropriate fractions provided the title acetylpyrazolidine. The resulting mixture was concentrated under vacuum Collection and concentration of appropriate fractions

Conditions: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of (2R)-2-(N-tert-butoxycarbonyl-N-methylamino)-3-phenylpropionic acid (0.27 g, 0.96 mmol) in methylene chloride (10 ml) was added 1-hydroxy-7-azabenzotriazole (0.13 g, 0.96 mmol) and 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide hydrochloride (0.18 g, 0.96 mmol) and the mixture was cooled to 0° C. Then acetic acid N'-methylhydrazide (0.19 g, 0.96 mmol) and diisopropylethylamine (0.41 ml, 2.40 mmol) were added and the mixture was stirred at room temperature overnight. Then methylene chloride (50 ml) was added and the mixture was washed with water (10 ml), saturated sodium bicarbonate (10 ml), brine (10 ml), dried (MgSO4), filtered and concentrated in vacuo to give 0.35 g (125%) of crude N-[(1R)-2-(N'-acetyl-N-methylhydrazino)-1-benzyl-2-oxoethyl]-N-methylcarbamic acid tert-butyl ester as a colourless oil. the mixture was washed with water (10 ml), saturated sodium bicarbonate (10 ml), brine (10 ml) dried (MgSO4) filtered concentrated in vacuo

Conditions: temp:120.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of methyl 8-[(4-methoxybenzyl)oxy]-5-vinyl-[1,6]-naphthyridine-7-carboxylate (0.26 g, 0.73 mmol), paraformaldehyde (96 mg), and 1-acetyl-2-methylhydrazine (0.22 g, 2.45 mmol; J. Org. Chem. 1972, 37, 3608) in toluene (15 mL) was heated in an oil bath at 120° C. for 1.5 hour. The resulting mixture was concentrated under vacuum. The residue was subjected to column chromatography on silica gel eluting first with a gradient of 0-5% methanol in ethyl acetate. Collection and concentration of appropriate fractions provided the title acetylpyrazolidine. The resulting mixture was concentrated under vacuum Collection and concentration of appropriate fractions