Hydrochloric Acid → Ethyl Pyruvate 4-Chloro-3-Fluorophenylhydrazone

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A solution of sodium nitrite (4.76 g, 0.069 mol) in water (6.3 mL) was added dropwise to an ice cooled mixture of 4-chloro-3-fluoroaniline (J. Am. Chem. Soc., 1996, 61, 5130-5133) (10.00 g, 0.069 mol), water (167 mL) and 37% hydrochloric acid (167 mL). After 20 minutes potassium acetate (9.81 g, 0.10 mol) was added, and then a solution of ethyl 2-methylacetoacetate (9.95 g, 0.069 mol), potassium acetate (9.81 g, 0.10 mol) in methanol (67 mL) was dropped while cooling on the ice bad. Reaction was stirred at 0° C. for 3 hours, then extracted with diethyl ether. Organic layer was washed with brine and dried. Removal of the solvent furnished a red oily residue that was treated with ethanol (100 mL) and stirred at room temperature overnight. The solid which formed was filtered a recrystallized from ethanol to give 5.4 g (30%) of title compound, mp 161-163° C. (from ethanol).

Herkunft & Nachweise