Abstract
Oxygen was blown into a mixture of cumene (1), m- and p-diisopropylbenzenes [(2) and (3)], p-cymene (4), 1-isopropenyl-4-methylbenzene (5), stylene (6), isosafrole (7), anethole (8) or isoeugenole (9) in a polar aprotic solvents (DMSO, DMI, DMAc or DMF) for 3200h at 100120°C.
The oxidation of (1) (5) with isopropyl or isopropenyl group in DMSO at 100120°C took place to give acetylbenzene (10), 1-acetyl-3-isopropylbenzene (12), 1-acetyl-4-isopropylbenzene (14), and 1-acetyl-4-methylbenzene (16) in high selectivity (100%), while a similar oxidation in DMF or DMI yielded 2-phenyl-2-propanol (11), 2- (m-isopropylphenyl) -2-propanol (13), 2- (p-isopropylphenyl) -2-propanol (15), and 2- (p-methylphenyl) -2-propanol (17).
In the case of (6) (8) with vinyl or allyl group, in DMSO at 100120°C gave benzaldehyde (18), piperonylacetone (22), and (p-methoxyphenyl) acetone (23) as major products. In DMI, DMAc or DMF at 100120°C, the oxidation of (6) (9) gave (18), 1-phenyl-1, 2-epoxyethane (19) that was a precurser of (10), piperonal (20), anisaldehyde (22), (23), 1- (p-methoxyphenyl) -1, 2-epoxypropane (24) that was a precurser of (23), and vaniline (25).
