1.3.5- Triazine, diphenyl-, Chichibabin amination

Diphenyl-l,3,5-triazine undergoes a Chichibabin-type amination reaction, the first example of this reaction to be reported for the 1,3,5-triazines. The 2-methylthio derivative (37 X = MeS) reacts exclusively via an Sn(ANRORC) mechanism rather than the SNAE mechanism (Scheme 21) (76RTC113). 

Substituted triazines have been subjected to amination with potassium amide in liquid ammonia. With 2,4-diphenyl-l,3,5-triazine (260), treatment with potassium amide in liquid ammonia afforded a typical Chichibabin product, 2-amino-4,6-diphenyl-I,3,5-triazine (261) (Scheme 89) (76RTC 113). Through labeling experiments, it was established that the amination was not occurring via an Sn(ANRORC) mechanism, but rather by an Sn(AE) process. However, Sn(ANRORC) does occur during the amination of phenyl-1,3,5-triazine, and this has been elaborated upon in Section II,B,1. 

The amination of 2.4-diphenyl-1,3,5-triazine (7, X = H) with potassium amide in anhydrous liquid ammonia at -33°C occurs by a Chichibabin-type reaction, i.e. replacement of H" by NH via nucleophilic substitution involving an addition-elimination process (SsAE). In contrast, the 2-methylsulfanyl derivative 7 (X = SMe) is aminated nearly exclusively by a ringopening-ring-closing sequence [Sn(ANRORC)].52... 

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