Zeolites in the Synthesis of 1-Alkyl-2-oxonicotinonitriles

Abstract

Cyclocondensations of acetylacetone with cyanoacetamide or N-alkylcyanoacetamides in the presence of NaA zeolite afford 4,6-dimethyl-2-oxonicotinonitrile or 1-alkyl-4,6-dimethyl-2-oxonicotinonitriles respectively. The condensation of 3-hydroxyiminopenta-2,4-dione with cyanoacetamide in the presence of NaA zeolite furnished 4,6-dimethyl-5-nitroso-2-oxonicotinonitrile.2-Oxonicotinonitriles exhibit vasodilating effect [1] and immunosuppressive activity [2]. They are constituents of plant growth regulators, herbicides, and defoliants for they are modulators of chlorophyll biosynthesis in plants [3].2-Oxonicotinonitriles IIV are commonly prepared by the cyclocondensation of cyanoacetamide or its N-alkyl derivatives with acetylacetone [4] or 3-hydroxyiminopenta-2,4-dione [5]. The reaction is carried out either in a buffer solution at pH 9.1 [6] or in the presence of catalysts. As catalysts were applied potassium carbonate [6], secondary and tertiary amines [47], and lipase from Candida cylindracea [8].We suggested to use as catalyst in this reaction the NaA zeolite for zeolites were known to catalyse the aldol condensation of acetone [9]. It actually proved that acetylacetone entered into cyclocondensation with the cyanoacetamide (V) and N-alkylcyanoacetamides VI and VII in the presence of NaA zeolite. The reaction gave rise to 1-alkyl-4,6-dimethyl-2-oxonicotinonitriles IIII. 0H&2&+ &20H &1&+ &21+5 1D$ 1 0H &1 2 5 0H , ,,, B 9 9,, B

Synthesis and reactions of 3‐cyano‐4,6‐dimethyl‐2‐pyridone

“…Thus, despite the large number of methods known for their synthesis, new procedures are continuously being developed [8]. Many catalysts have been used in the synthesis of 2‐pyridone from 1,3‐diketones, such as zeolites [9], lipase enzymes [10–12], and triethylamine [13]. Microwave irradiation in preparing N ‐substituted pyridones has also been reported recently [14].…”