N-Arylcarbamic acid esters

Friesen reported as early as 1929 on the herbicidal activity of an N-arylcarbamic acid ester, phenyl urethane, however, its action causing abnormal growth on wheat and oats was utilised for practical purposes only IS years later. 

Templeman and Sexton (1945,1946) found that N-phenylcarbamates are toxic to monocotyledons but not dicotyledons. Of this group the first herbicide used in agriculture was isopropyl N-phenylcarbamate (IPC, propham, 3). 

Propham is a selective soil herbicide used preemergence for the control of grass weeds in beet, cabbage, peas and lettuce. 

George et al. (19S4) studied the effect of the alcohol component (R) of N-phenylcarbamic acid esters on herbicidal activity. 

The selectivity of y-chloropropylester, chlorpropham (CIPC, 4) and that of sec-butylester correspond to that of IPC. 

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