The Reaction of (N-Isocyanimino)triphenylphosphorane with Biacetyl in the Presence of Aromatic Carboxylic Acids: Efficient One-Pot Three-Component Reaction for the Synthesis of 3-(5-Aryl-1,3,4-oxadiazol-2-yl)-3-hydroxybutan-2-one Derivatives
Reactions of biacetyl (=butane‐2,3‐dione) with (N‐isocyanimino)triphenylphosphorane in the presence of aromatic carboxylic acids proceed smoothly at room temperature and under neutral conditions to afford 3‐(5‐aryl‐1,3,4‐oxadiazol‐2‐yl)‐3‐hydroxybutan‐2‐one derivatives in high yields.
GRAPHICAL ABSTRACT ABSTRACT Reaction of N-isocyaniminotriphenylphosphorane with biacetyl in the presence of a carboxylic acid in water proceeds smoothly at RT (20–26°C) and neutral conditions to afford sterically congested 1,3,4-oxadiazole derivatives in high yields. The reaction proceeds smoothly and clearly under mild conditions and no side reactions were observed.