Table 1.

Optimization of the reaction conditions for phloretic acid and p-toluidine.

Entry	Catalyst	t [h]	T [°C]	Yield [%]
1	2 mol%	2	60–65	trace
2	2 mol%	2	80–85	30
3	2 mol%	2	100–105	88
4	2 mol%	2	120–125	95
5	2 mol%	2	160–165	94
6	2 mol%	0.5	120–125	52
7	none	2	120–125	71
8	none	5	120–125	85
9	0.1 mol%	2	120–125	79
10	0.1 mol%	3	120–125	87
11	0.1 mol%	5	120–125	93