Strategies for protecting and manipulating triazine derivatives

Aminotriazine derivatives are available in two steps by treating chlorotriazines with acid-labile benzylic amines including triphenylmethylamine, diphenylmethylamine, and 2,4-dimethoxybenzyl-amine (Dmb-amine), followed by deprotection using trifluoroacetic acid. This high yielding (85–99%) protocol is a milder alternative to the traditional method that uses ammonia and high temperature as a route to aminotriazine derivatives. The nucleophilic substitution reaction that installs the benzylic amine on monochlorotriazine herbicide derivatives may be performed using conventional heating. Alternatively, a microwave reactor can be used to decrease the reaction times 100-fold. The intermediates in these syntheses are soluble in a range of organic solvents and amenable to chromatography. In some cases when dimethoxybenzyl groups are used, oligomerization of the dimethoxybenzyl side product upon treatment with trifluoroacetic acid yields a precipitate that facilitates purification by simple filtration.