N-Substituted a-chloroacetamides

The herbicidal effect of N-substituted a-chloroacetamides has been described by Hamm and Speziale (1956a,b). Of the great number of compounds prepared, N,N-diethylchloroacetamide (CDEA, 1) and N,N-diallylchloroacetamide (CDAA, allidochlor, 2) exhibit marked biological activity. 

Of the two aliphatic chloroacetamides allidochlor is the more active herbicide and has been introduced into agricultural use. 

Allidochlor is a liquid of pungent odour, slightly soluble in water. It is prepared by the reaction of diallylamine and chloroacetyl chloride in an inert solvent at 0°C. For the binding of hydrochloric acid NaOH is used (Hamm and Speziale, 1956a). 

Allidochlor is a selective preemergence herbicide used at rates of 4-5 kg active ingredient/ha for the control of annual grass weeds and some broad-leaved weeds. It is selective in maize, millet, soybeans, vegetables and sugar cane. 

An interesting side-effect is its increasing selectivity of thiol carbamate herbicides in maize. 

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The most important compounds are the N-substituted a-chloroacetamides, particularly the substituted anilides, which are used partly for preemergence treatment and partly for postemergence treatment of many kinds of crops. 

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