Aerobic oxidation of 1,3,5-triisopropylbenzene using N-hydroxyphthalimide (NHPI) as key catalyst
摘要:
The first systematic study on the aerobic oxidation of 1,3,5-triisopropylbenzene was examined by the use of N-hydroxyphthalimide (NHPI) as a key catalyst. It was found that 1,3,5-triisopropylbenzene was efficiently oxidized with 02 in the presence of a catalytic amount of NHPI and azobisisobutyronitrile (AIBN) at 75 degrees C. Upon treatment of the resulting products with sulfuric acid followed by acetic anhydride led to 5-acetoxy-1,3-diisopropyl benzene and 3,5-diacetoxy-1-isopropyl benzene as major products and a small amount of 1,3,5-triacetoxybenzene. When t-butyl peroxypivalate (BPP) was employed as a radical initiator, the oxidation could be achieved in good yield even at 50 degrees C. This oxidation provides a facile method for preparing phenol derivatives bearing an isopropyl moiety, which can be used as pharmaceutical starting materials. (c) 2005 Elsevier Ltd. All rights reserved.
The first systematic study on the aerobic oxidation of 1,3,5-triisopropylbenzene was examined by the use of N-hydroxyphthalimide (NHPI) as a key catalyst. It was found that 1,3,5-triisopropylbenzene was efficiently oxidized with 02 in the presence of a catalytic amount of NHPI and azobisisobutyronitrile (AIBN) at 75 degrees C. Upon treatment of the resulting products with sulfuric acid followed by acetic anhydride led to 5-acetoxy-1,3-diisopropyl benzene and 3,5-diacetoxy-1-isopropyl benzene as major products and a small amount of 1,3,5-triacetoxybenzene. When t-butyl peroxypivalate (BPP) was employed as a radical initiator, the oxidation could be achieved in good yield even at 50 degrees C. This oxidation provides a facile method for preparing phenol derivatives bearing an isopropyl moiety, which can be used as pharmaceutical starting materials. (c) 2005 Elsevier Ltd. All rights reserved.