Evaluation of various catalyst for the synthesis of picolinate and picolinic acid derivatives in comparison with UiO-66(Zr)-N(CH₂PO₃H₂)₂ in ethanol under room temperature conditions.

Entry	Catalyst	Amount of catalyst	Time (min)	Yield (%)
1	[Py-SO3H]Cl (ref. 49)	10 mol%	120	40
2	Fe3O4	10 mg	120	—
3	Al(HSO4)3	10 mol%	90	45
4	H3[P(W3O10)4]·XH2O	10 mol%	80	50
5	p-TSA	10 mol%	60	60
6	SSA (ref. 50 and 51)	10 mg	80	35
7	GTBSA (ref. 52)	10 mol%	70	58
8	[PVI-SO3H]Cl (ref. 53)	10 mol%	65	70
9	UiO-66-NH2	5 mg	120	24
10	H3PO4	10 mol%	80	70
11	UiO-66-N(CH2PO3H2)2	5 mg	60	88
12	H3PO3	5 mol%	85	70