A Clean, Simple, and Efficient Synthesis of 2-Substituted Aryl (Indolyl) Kojic Acid Derivatives by Kaolin/Ag Nanocomposite as a Reusable Catalyst: A Green Protocol

Table 2

Evaluation of the activity of different catalysts for the synthesis of 4a.

Entry	Catalyst	Yield^a/%
1	KAl(SO4)2·12H2O	60
2	Kaolin	83
3	Silver NPs	92
4	Kaolin/Ag nanocomposite	98

aReaction conditions: 60 min at 90°C in solvent-free conditions.