Oxidation of 2-methoxy-6-(1-methylethyl)naphthalene with oxygen

Aerobic oxidation of isopropylaromatic hydrocarbons to hydroperoxides catalyzed by N-hydroxyphthalimide

“…This study complements the papers published thus far on the oxidation of isopropylarenes in the presence of NHPI [6][7][8][9][10][11][12] with respect to the range of the influence of temperature and the electron-donating substituents (methoxy, phenyl) on the course of the reaction as well as catalyst recovery and air application. The oxidation of hydrocarbons 2, 4 and 7 in the presence of NHPI to hydroperoxides are reported for the first time.…”

“…S3 and S4). The aim was to indicate that the previously observed decrease in the conversion rate at temperature greater than 60°C in the case of the oxidation of 3 and 5, reported in our previous works [9,10], was not a result of the presence of methoxy group in the aromatic rings of 3 and 5.…”

“…2-Isopropylnaphthalene was obtained by the crystallization of the technical product according to [19]. 2-Methoxy-6-(1-methylethyl)naphthalene was prepared from 2,6-diisopropylnaphthalene according to the procedure described in [10]. The other starting materials and catalyst were used without further purification.…”

“…The oxidation processes of isopropylaromatic hydrocarbons to hydroperoxides, as recently shown, can be catalyzed by N-hydroxyphthalimide (NHPI) [4][5][6][7][8][9][10][11] as well as its derivatives [12]. Literature data concerning the NHPI-catalyzed oxidation of isopropylarenes are collected in Table 1.…”

“…For example phenol from cumene was obtained in a maximum yield of 77 % [6], whereas 2,6-dihydroxynaphthalene was obtained in 81 % yield [8]. Recently, we have described the NHPI-catalyzed oxidations of isopropylarenes with a methoxy group in the aromatic ring, i.e., of 1-methoxy-4-(1-methylethyl)benzene (3) [9] and 2-methoxy-6-(1-methylethyl)naphthalene (5) [10] to hydroperoxides. The corresponding hydroperoxides were obtained in yields of 58 and 87 % (conversion 60 and 92 %), respectively, when the processes were carried out at 60°C in benzonitrile as a solvent.…”