One-pot room-temperature conversion of cyclohexane to adipic acid by ozone and UV light

Abstract

Nitric acid oxidation of cyclohexane accounts for ~95% of the worldwide adipic acid production and is also responsible for ~5 to 8% of the annual worldwide anthropogenic emission of the ozone-depleting greenhouse gas nitrous oxide (N2O). Here we report a N2O-free process for adipic acid synthesis. Treatment of neat cyclohexane, cyclohexanol, or cyclohexanone with ozone at room temperature and 1 atmosphere of pressure affords adipic acid as a solid precipitate. Addition of acidic water or exposure to ultraviolet (UV) light irradiation (or a combination of both) dramatically enhances the oxidative conversion of cyclohexane to adipic acid.

Tungsten doped mesoporous SBA‐16 as novel heterogeneous catalysts for oxidation of cyclopentene to glutaric acid

“…However, these methods are inconvenient and unsuitable for large‐scale synthesis. Amino acids, alkanes, ketones, alcohols, and 1,3‐dicarbonyl derivatives have also been reported to manufacture carboxylic acids, but they are rarely used or required complicated multi‐step to fabricate GAC. Phase‐transfer catalysts W/[CH 3 ( n ‐C 8 H 17 ) 3 N]HSO 4 and [π‐C 5 H 5 NC 16 H 33 ] 3 [PW 4 O 16 ] have been proposed for selective oxidation of olefins using H 2 O 2 by Noyori et al .…”

A Green Route to Produce Adipic Acid on TiO2–Fe2O3 Nanocomposites

“…Cyclohexene oxidation with H 2 O 2 is another alternative to producing adipic acid (Scheme ), which is one of the most widely used dicarboxylic acids in the chemical industry. It can be also used for the manufacture of nylon 6,6 polyamide, polyurethanes, plasticizers, and other pharmaceutical chemicals …”

Morphology‐Reserved Synthesis of Discrete Nanosheets of CuO@SAPO‐34 and Pore Mouth Catalysis for One‐Pot Oxidation of Cyclohexane

“…In the past decades, great efforts have been devoted to green methods for the production of adipic acid. The most recent significant progress is reported by Hwang et al., using ozone as oxidant under irradiation with UV light . However, the direct oxidation of cyclohexane to adipic acid by O 2 in a heterogeneous process remains a great challenge at the present time .…”