ethyl 2-oxo-4-phenylbut-3-enoate

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

Procedure: To the benzalpyruvic acid of step A in water-saturated ethyl acetate there was added triethylamine (56.2 g, 0.55 mol) at a rate less than 0.5 ml/min with good agitation. Water was then azeotropically removed by vacuum distillation and the benzalpyruvic acid concentration readjusted to 120 g/l with dry ethyl acetate. Ethyl chloroformate (59.7 g, 0.55 mol) was then added over a one hour period at 20°-25° C. followed by a one hour age. The mixture was cooled to 0°-5° C. and quenched with 350 ml of cold water. The aqueous layer was discarded and the organic layer was washed with cold (0°-5° C.) 5% sodium bicarbonate solution (350 ml) followed by cold (0°-5° C.) 5% sodium chloride (350 ml). The ethyl acetate was removed by vacuum concentration affording crude ethyl benzalpyruvate in a yield of 95-97%. The ester was subsequently purified by distillation using a short-path wiped film evaporator (WFE) apparatus (150° C., 0.1 mm Hg). Water was then azeotropically removed by vacuum distillation the benzalpyruvic acid concentration The mixture was cooled to 0°-5° C. quenched with 350 ml of cold water the organic layer was washed with cold (0°-5° C.) 5% sodium bicarbonate solution (350 ml) followed by cold (0°-5° C.) 5% sodium chloride (350 ml) The ethyl acetate was removed by vacuum concentration

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

Procedure: Furthermore, the pyruvic acid compound (I) can also be produced, for example, in accordance with: (1) the process in which benzaldehyde and sodium pyruvate are condensed together to give benzalpyruvic acid, and the benzalpyruvic acid is then reacted with ethyl chloroformate to give ethyl benzalpyruvate, and the ethyl benzalpyruvate is then reduced [EP387058]; or (2) the process in which phenetyl bromide is reacted with carbon monoxide in the presence of a cobalt carbonyl catalyst [J. Mol. Cat., 88, 295(1994)]. The process for producing the pyruvic acid compound (I) as the starting material is not limited to these processes, either of which can be used as the production process for the starting material in the present invention.

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

Procedure: To the benzalpyruvic acid of step A in water-saturated ethyl acetate there was added triethylamine (56.2 g, 0.55 mol) at a rate less than 0.5 ml/min with good agitation. Water was then azeotropically removed by vacuum distillation and the benzalpyruvic acid concentration readjusted to 120 g/l with dry ethyl acetate. Ethyl chloroformate (59.7 g, 0.55 mol) was then added over a one hour period at 20°-25° C. followed by a one hour age. The mixture was cooled to 0°-5° C. and quenched with 350 ml of cold water. The aqueous layer was discarded and the organic layer was washed with cold (0°-5° C.) 5% sodium bicarbonate solution (350 ml) followed by cold (0°-5° C.) 5% sodium chloride (350 ml). The ethyl acetate was removed by vacuum concentration affording crude ethyl benzalpyruvate in a yield of 95-97%. The ester was subsequently purified by distillation using a short-path wiped film evaporator (WFE) apparatus (150° C., 0.1 mm Hg). Water was then azeotropically removed by vacuum distillation the benzalpyruvic acid concentration The mixture was cooled to 0°-5° C. quenched with 350 ml of cold water the organic layer was washed with cold (0°-5° C.) 5% sodium bicarbonate solution (350 ml) followed by cold (0°-5° C.) 5% sodium chloride (350 ml) The ethyl acetate was removed by vacuum concentration