solvent in either or ethyl acetate and water the organic layer is then separated preferably washed with a suitable acid one or more times dried filtered and thereafter concentrated to a residue finally the resultant product of formula iv is crystallized using a suitable solvent or solvent pair such as ethyl acetate hexane ether or ether hexane when the starting compound is 6 4 methylphenyl 4 6 dioxohexanoic acid the first step of the synthesis yields the novel compound of formula ii where r is ch 3 5 1 4 methylphenyl 1 oxo 1 ethanyl 2 ylidene 2 oxo 2 3 4 5 tetrahydrofuran the second step yields the novel compound of formula iii where r is ch 3 6 4 methylphenyl 4 6 dioxo n hydroxy n methylpropanamide the final step yields 3 5 4 methylphenyl 1 4 methoxyphenyl 3 pyrazoloyl n hydroxy n methylpropanamide when the starting compound is 6 4 chlorophenyl 4 6 dioxohexanoic acid the first step of the synthesis yields the novel compound of formula ii where r is cl 5 1 4 chlorophenyl 1 oxo 1 ethanyl 2 ylidene 2 oxo 2 3 4 5 tetrahydrofuran the second step yields the novel compound of formula iii where r is cl 6 4 chlorophenyl 4 6 dioxo n hydroxy n methylpropanamide the final step yields tepoxalin 3 5 4 chlorophenyl 1 4 methoxyphenyl 3 pyrazoloyl n hydroxy n methylpropanamide the present invention is also directed to novel intermediate compounds.