Transamination of Amides

2-Carbamoyl-3-hydroxypyrazine refluxed with aniline gave 2-hydroxy-3-7V-phenylcarbamoylpyrazine (1055) and 2-amino-3-carbamoyl-5,6-diphenylpyrazine refluxed with benzylamine gave 2-amino-3-A -benzylcarbamoyl-5,6-diphenylpyrazine but a similar reaction with piperidine was unsuccessful (451). 3-Methylamino-2-yV-methylcarbamoyl-5-phenylpyrazine was unchanged when heated with liquid ammonia in dry ethanol at 210° for 2 hours (453). 2,6-Diamino-3-carbamoyl-5-chloropyrazine in isopropanol with 1 mol of potassium hydroxide and 1 -amidino- 

5-dimethylpyrazole nitrate at 0° gave 2,6-diamino-3-chloro-5-guanidinocarbonyl-pyrazine (and W-substituted analogues were prepared similarly) (1412). 

---

Transamination of amide acetals is possible and of synthetic value if high boiling, strongly nucleophilic secondary amines are to be introduced. Ketene 0,iV-acetals add alcohols to yield amide acetals (468 equation 216). From tetrakis(dimethylamino)ethylene and methanol a mixture of amide acetals, e.g. (469) and (470 equation 217), is formed. Azavinylogous formamide acetals (471 equation 218) are accessible by the action of formide acetals on tris(formylamino)methane or form-amide. ... 

---