Table 2.

Approaches for the oxidation of 2-methylnaphthol to menadione (10).

Entry	Conditions	Catalyst	Yield (%)	Ref.
1	H2O2 (60%), MeOH, reflux, 20 min	Br2, H2SO4	90	[66]
2	H2O2 (30%), MeCN, 80 °C, 30 min	Ti-MMM-2	78	[65]
3	H2O2 (30%), MeCN, reflux, 40 min	TiSBA-15	93	[67]
4	H2O2, acetone, 70 °C, 2 h	Nb2O2-SiO2	60	[68]
5	H2O2, MeCN, 75 °C, 45 min	NbSBA-15(2.2pH)	97	[69]
6	H2O2/CH3COOH, CO2 (150 bar), 50 °C, 2 h	Au (5%)/HPS	89	[70]
7	H2O2 (30%), TAA, 0 °C, 1 h	FeCl3·H2O/H2Pydic/benzylamine	55	[55]
8	CO2, benzene/H2O, 50 °C, 25 min	HPA-n	81a	[71]
9	O2 (3 atm), toluene, 80 °C, 6 h	Au/TiO2	57	[72]
10	O2 (3 atm), toluene, 80 °C, 6 h	Au/C-2	49	[72]
11	O2 (3 atm), toluene, 80 °C, 8 h	–	80	[73]
12	t-BuOOH, DCM, 80 °C, 1 h	FePcS-SiO2	55	[74]

^aConversion.