Ethyl 4-methyl-2-(4-methylbenzoylamino)-3-oxopentanoate → Ethyl 5-isopropyl-2-p-tolyloxazole-4-carboxylate

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Reaction Steps

13 g of ethyl 4-methyl-2-(4-methylbenzoylamino)-3-oxopentanoate in 80 ml of phosphorus oxychloride are heated to the boil under reflux for 2 h. The phosphorus oxychloride is removed under reduced pressure and the resulting residue is dissolved in 200 ml of dichloromethane, washed three times with saturated NaHCO3 solution and dried over MgSO4, and the solvent is then removed under reduced pressure. This gives 11 g of ethyl 5-isopropyl-2-p-tolyloxazole-4-carboxylate as a brownish solid. C16H19NO3 (273.33), MS (ESI)=292 (M+H+), Rf (n-heptane:ethyl acetate)=2:1)=0.43.

Provenance & Evidence