Transformation of 2-(4-chloro-5H-1,2,3-dithiazol-5-ylideneamino)-6-ethoxy-4-phenylpyridine-3,5-dicarbonitrile into 4-aminopyrido[2,3-d]pyrimidines and 2-(pyrid-2-yl)guanidines

摘要: Abstract The reactions of 2-(4-chloro-5H-1,2,3-dithiazol-5-ylideneamino)-6-ethoxy-4-phenylpyridine-3,5-dicarbonitrile (14) with a range primary and secondary amines are investigated. Treatment n-BuNH2 BnNH2 gave 1,3-di-n-butyl- 1,3-dibenzyl-2-(3,5-dicyano-6-ethoxy-4-phenylpyrid-2-yl)guanidines 15a (32%) 15b (82%), respectively. While treatment Et2NH, n-Pr2NH or Bn2NH the analogous 4-dialkylaminopyrido[2,3-d]pyrimidines 16c–e in high yields. dithiazole 14 pyrrolidine, piperidine morpholine 16f–h, 2-aminopyridine 13 2-(diamino-1-ylmethyleneamino)-6-ethoxy-4-phenylpyridine-3,5-dicarbonitriles 15f–h. 16f–h converted to 2-(dialkylamino-1-ylmethyleneamino)-6-ethoxy-4-phenylpyridine-3,5-dicarbonitriles 15f–h upon further reaction excess dialkylamines. structure origins two side products 17 18 also discussed. Tentative mechanisms for these transformations proposed.