Tetrahydrophthalimide and

The fungitoxic N-perhalogenmethylmercapto moiety was introduced for plant protection in 1950 The. two fungicides captan(l) (N-(trichloromethylthio)-tetrahydrophthalimide and folpet(2) (N-(trichlorome-thylthio)phthalimide) contain a perchlorinated methyl-thio group (1 ). About a decade later substitution of fluorine for one of the chlorines in the perchloro-... 

Captan is not toxic to warm-blooded animals. The acute oral lDj for rats is 9000 mg/ kg. No evidence of chronic toxicity has been found (Boyd and Carsky, 1971 Seidler er a/., 1971). It is only slightly irritating to the skin. Captan is rapidly absorbed and metabolised in warm-blooded animals, almost the whole quantity being excreted in the feces within 3 days. Unchanged captan could not be detected in rats tetrahydrophthalimide and tetrahydrophthalic acid were found transitorily in the blood. 

Replacement of the tetrahydrophthalimide and other heterocyclic rings such as the triazolinone 32 with the uracil 33 ring resulted in a significant improvement in biological activity, particularly when applied pre-emergently [67] (Table 3.2). 

---