2-methoxyethylhydrazine;hydrochloride

Conditions: temp:60.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 2-Methoxyethylhydrazine hydrochloride (Ref: J. Med. Chem. (1967) 11 (1) 79-83) (1.07 g, 8.5 mmol) and ethyl-4-dimethylamino-2-oxo-but-3-enoate (1.5 g, 8.5 mmol) were dissolved in ethanol (10 ml) and heated at 60° C. for 7 hours. The solvent was evaporated in vacuo and the residue was partitioned between ethyl acetate (80 ml) and dilute sodium carbonate solution (40 ml). The organic layer was dried over anhydrous Na2SO4 and the solvent removed in vacuo to give a brown gum. This material was chromatographed on silica gel (30 g) using 40% to 20% heptane in ethyl acetate. The higher running product was collected to give 2-(2-methoxyethyl)-2H-pyrazole-3-carboxylic acid ethyl ester as 750 mg of a mobile yellow oil. The lower running product was collected to give 1-(2-methoxyethyl)-1H-pyrazole-3-carboxylic acid ethyl ester as 360 mg of a yellow oil. The solvent was evaporated in vacuo the residue was partitioned between ethyl acetate (80 ml) and dilute sodium carbonate solution (40 ml) The organic layer was dried over anhydrous Na2SO4 the solvent removed in vacuo to give a brown gum This material was chromatographed on silica gel (30 g) was collected