NEW MATERIAL:A compound expressed by formula I (R1 is aryl or alkyl; R2 and R3 are H, alkyl or aryl; R4 is alkyl).
EXAMPLE: N-{(N'-Phenyl)carbamoyl}dehydrovaline ethylester.
USE: An intermediate for producing an amino acid and hydantoin based herbicide.
PREPARATION: An urea derivative expressed by formula II is reacted with a α-ketocarboxylic acid ester derivative expressed by formula III in the presence of a base catalyst (e.g., Na2CO3 or K2CO3) or an acid catalyst (e.g., H2SO4 or p-toluenesulfonic acid) to provide the compound expressed by formula I. The acid catalyst is preferably used at an amount of 0.01W0.5 equivalent based on the substrate. The above-mentioned reaction is preferably carried out in an organic solvent such as benzene, toluene or dioxane.
FUJITA ATSUKO
FUCHIGAMI TAKAMASA
HIROSE HIROAKI
YOKOTA MASAHIRO
NAGATO SHOIN
