Rate increase in consecutive nucleophilic aromatic substitution reactions of trichlorotrinitrobenzene: The synthesis of 1-(alkylamino)-3,5-dichloro-2,4,6-trinitrobenzenes

The title compounds are formed by the nucleophilic aromatic substitution reaction between sym-trichlorotrinitrobenzene and amines. The yields and relative rates of formation depend critically on the degree of alkylation of the nucleophile. Contrary to the usual behavior, the introduction of a second and third donor is facilitated in the case of ammonia and monoalkylamines, while this is not the case for secondary amines. This behavior is rationalized on the basis of intramolecular hydrogen bonding and substantiated by an X-ray analysis of 3,5-dichloro-2,4,6-trinitroaniline.