Table 1.

Different approaches of 2-methylnaphthalene oxidation to menadione.

Entry	Conditions	Catalyst	Yield (%)	Ref.
1	CrO3, H2O, AcOH, 85–90 °C, 1 h	–	38–42	[47]
2	Na2Cr2O7·H2O, H2SO4, CCl4, 80 to 0 °C, 15 min	–	48–62	[48]
3	H5IO6, CH3CN, 5 °C, 1 h	CrO3	61	[49]
4	H2O2 (60%), AcOH, 50 °C, 8 h	palladium(II)-resin	50–60	[50]
5	H2O2 (85%), Ac2O, AcOH, 40 °C, N2, 4 h	CH3ReO3	46	[51]
6	H2O2 (30%), AcOH, 100 °C, 3 h	–	86	[52]
7	H2O2 (0.2 M), AcOH, rt, 24 h	iron(III) salts	13	[53]
8	H2O2 (30%), AcOH, 60 °C, 3 h	MnPc	60	[54]
9	H2O2 (30%), TAA, rt, 1.5 h	FeCl3·H2O/H2Pydic/benzylamine	44	[55]
10	H2O2, AcOH, 100 °C, 6 h	SeMCM-41	99a	[56]
11	H2O2 (30%), AcOH, H2SO4, 60–80 °C, 1 h	[(DIPAPTES)PdCl2] or [SiO2(DIPAPES)PdCl2]	52 or 59	[57]
12	H2O2 (35%), CH3CN, AcOH, reflux, 8 h	GO@CHONHRN(CH2PPh2)2PdCl2	99a	[58]
13	H2O2 (35%), CH3CN, AcOH, H2SO4, reflux, 12 h	L1-iron(III)	79a	[59]
14	H2O2 (35%), CH3CN, H2O, 60 °C, 20 min	H[CuII(ttb)(H2O)3]2[CuII(ttb)Cl]2 [PW12O40]·4H2O	78a	[60]
15	CH3COOOH, AcOH, 80 °C, 2 h	Au/HPS	72	[61]
16	O3, AcOH, 160 °C	chromium(III) and manganese(II) salts	70	[62]

^aConversion.