Investigation of oxidation of benzaldehyde using copper(ii) and iron(iii) salts at different reaction conditions.

Entry	Condition	Additive	Conversion	Benzoic acid yielda
1	200 °C, 24 h	None	4%	3%
2	200 °C, 24 h	0.2 m CuCl2	8%	7%
3	200 °C, 24 h	0.2 m CuSO4	9%	8%
4	200 °C, 24 h	0.2 m Cu(OAc)2	6%	5%
5	200 °C, 0.5 h	0.2 m Cu(NO3)2	12%	10%
6	200 °C, 1 h	0.2 m Cu(NO3)2	25%	24%
7	200 °C, 2 h	0.2 m Cu(NO3)2	30%	26%
8	200 °C, 2 h	0.1 m Cu(NO3)2 + 0.1 m NaNO3	15%	13%
9	200 °C, 2 h	0.2 m NaNO3	11%	10%
10	200 °C, 24 h	0.2 m FeCl3	14%	13%
11	200 °C, 24 h	0.1 m Fe2(SO4)3	11%	10%
12	100 °C, 2 h	0.2 m Fe(NO3)3	39%	38%
13	140 °C, 2 h	0.2 m Fe(NO3)3	59%	57%
14	170 °C, 1 h	0.2 m Fe(NO3)3	62%	59%
15	200 °C, 0.5 h	0.2 m Fe(NO3)3	64%	60%
16	200 °C, 1 h	0.2 m Fe(NO3)3	>99%	94%
17	200 °C, 2 h	0.2 m Fe(NO3)3	>99%	98%
18	200 °C, 2 h	0.1 m Fe(NO3)3	>99%	90%
19	200 °C, 2 h	0.2 m FeCl3 + 0.2 m NaNO3	>99%	97%
20	200 °C, 2 h	0.2 m FeCl3 + 0.6 m NaNO3	>99%	98%
21	200 °C, 2 h	0.2 m Mg(NO3)2	23%	21%
22	200 °C, 2 h	0.2 m Ca(NO3)2	9%	8%

^aYield determined by gas chromatography.