Benzotriazol-l-ylmethyl amines

The most common form of the type e ring-closure reaction to afford 1,4-benzodiazepines is a l-endo-trig--ptoce,ss in which a substituted iminium derivative, typically generated in situ, is captured by the aryl ring. Cyclization of the A,iV -(bis-l,2,3-benzotriazol-l-ylmethyl)amine 104 by a Friedel-Crafts-type ring closure afforded the tetrahydro-1,4-... 

Aminomethylsamarium reagents are obtained from tosylmethylamines or benzotriazol-l-ylmethyl amines. Bis(benzotriazol-l-ylmethyfamines react with Smij and carbonyl compounds to form oxazolidines. In benzotriazolylmethyl derivatives either benzotriazole or the other functional group suffers reductive removal, depending on their relative reduction potentials. 

Dihydro-2/r-l,3>5-thiadiazines 270 can be synthesized via [3+3] cycloaddition reactions. Thus, starting from N-substituted A, A -bis(l//-l,2,3-benzotriazol-l-ylmethyl)amines 271 containing two leaving groups, as the equivalent of 1,3-bielectrophiles, and thioamides as 1,3-binucleophiles, these components undergo a Lewis acid-promoted condensation to afford 3,4-dihydro-2//-l,3,5-thiadiazines 270 (Scheme 56) <2002JOC4960>. 

Dihydro-2//-l,3,5-thiadiazines containing a ring carbonyl or thiocarbonyl group are synthesized from reaction of thioamides with phenoxycarbonyl isocyanate, dimerization of thiocarbamoylisothiocyanates, or dimerization of carbamoyl isocyanates. The latter two [4-1-2] cycloaddition reactions complement the tabulated list of dienes and dienophiles presented in Table 2 (Section 9.09.9.2). 3,6-Disubstituted-3,4-dihydro-2//-l,3,5-thiadiazines are synthesized by treatment of N-substituted A, Wbis(l//-l,2,3-benzotriazol-l-ylmethyl)-amines with thioamides and zinc bromide (Section 9.09.9.1.3). 

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