History of Pencycuron Invention

In early 1950, many urea compounds with herbicidal activity had been studied and some of candidates were developed as practical herbicides. DCMU (N-3,4- 

DCMU was the lead compound for aiming at herbicidal activity. 

anticipating a new deployment, substituted benzyl was introduced instead of substituted phenyl at the N-position. A new general formula was pro- 

From these experiments we learnt that unintended small changes and scant signs observed in the study happened to be meaningful to future progress care- 

In reference to the chemical structure of NTN 15192 and NTN 16543, various N-alkyl compounds tvere tested (Table 16.2.2). However, none of the derivatives introducing those alkyls, such as methyl, ethyl, n-propyl, n-butyl, i-butyl, t-butyl, showed any biological activities. In contrast, i-propyl and s-butyl in the N-alkyl of the substructure showed obvious activity to R. solani. 4-Cl substitution at the benzyl ring was effective, but methyl or no substitution showed no effectiveness. Compounds substituted at phenyl ring were not effective as well. 

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