An Efficient Protocol for the Green and Solvent-Free Synthesis of Azine Derivatives at Room Temperature Using BiCl₃-Loaded Montmorillonite K10 as a New Recyclable Heterogeneous Catalyst

Table 1

Condensation of benzophenone azine (1 mmol) with acetophenone (1 mmol) using various catalysts at room temperature.

Entry	Catalyst	Grinding time (min)	% of azine^a
1	TiO2 (anatase)	5	Trace
2	TiO2-P25	5	Trace
3	Sulfated TiO2-P25	5	20
4	ZrO2	5	Trace
5	Sulfated ZrO2	5	15
6	ZnO (Merck)	5	Trace
7	TiO2 (Merck)	5	Trace
8	Mont K10	5	80
9	BiCl3-K10	2	98

^aYields with respect to benzophenone hydrazone.