Modification of conditions for the selective preparation of 2-amino-3-cyano-4-phenylpyridines

Abstract

We herein describe the modification of the experimental conditions for the synthesis of certain 2-amino-4-aryl-3-cyanopyridines from benzaldehyde, malononitrile, ammonium acetate and aminoketones. The outcome of the reaction proved to be highly dependent on the experimental procedure, occasionally giving rise to metaphthalodinitriles. Mechanistical proposals are also reported, in order to explain the observed dependence on the procedure.

2,6-Dicyanoaniline based donor-acceptor compounds: the facile synthesis of fluorescent 3,5-diaryl/hetaryl-2,6-dicyanoanilines

“…3 In addition, the 2,6-dicyanoanilines type of A-D-A system constitutes a part of the molecular framework of many biological important compounds such as quinolines, isoquinolines, tetrahydroisoquinolines, fluorenes, 9-oxofluorenes, benzofurans, naphthalenes, steroids, quinazolines, phenoxazines and coumarins. [4][5][6][7][8][9][10][11][12][13][14][15][16][17] The most studied derivatives of 2,6-dicyanoanilines are 3,5-disubstituted-2,6-dicyanoanilines, and many synthetic procedures and catalyst systems have been used in the synthesis of 3,5-disubstituted-2,6-dicyanoanilines. 3 They are generally obtained from one-pot reaction process via multicomponent domino coupling reaction pathway by using appropriate aldehyde and ketone.…”

Synthesis of (±)-7-Hydroxylycopodine

“…Stirring 3-propargylcyclohexanone ( 27 ) in 60% sulfuric acid for 16 h at 25 °C provided 1-hydroxybicyclo[3.3.1]nonan-3-one ( 28 ) in 76% yield, indicating that the protonated nitrogen of 16 is not necessary for the reaction (see Scheme ). Similar treatment of 3-propargylcyclopentanone ( 29 ) gave a complex mixture, and N -propargylpiperidine-4-one ( 30 ) was recovered unchanged from 60%, 80%, or concentrated sulfuric acid. These initial results suggest that this Prins reaction will be best suited for the synthesis of 1-hydroxybicyclo[3.3.1]nonan-3-ones.…”

Synthesis of 1,6‐Naphthyridine and Its Derivatives: A Systematic Review

“…Álvarez-Pérez and Marco-Contelles (2011) reported the one-pot synthesis of 2-amino-6-benzyl-4-phenyl-5,6,7,8-tetrahydro-1,6naphthyridine-3-carbonitrile (190) from N-benzylpiperidinone (187), benzaldehyde (189), malononitrile (134), and ammonium acetate (188) under refluxing condition (Scheme 48). [67] The yield obtained through this condition was (21 %) poor. To improve the yield, 2-benzylidenemalononitrile was prepared first and then treated with N-benzylpiperidinone followed by ammonium acetate.…”