Method for preparing benzil by performing catalytic oxidation on benzoin

Abstract

The invention belongs to the technical field of preparation of benzyl and provides a method for preparing benzil by performing catalytic oxidation on benzoin. According to the method, oxygen or air serves as an oxidizing agent, a composite catalyst consists of two components, namely vanadium oxide and nitrous acid ester, and the benzyl is prepared by performing catalytic oxidation on the benzoin at 60 to 120 DEG C. Compared with the stoichiometric chemistry oxidation methods such as traditional chromate oxidation method, the nitric acid oxidation method and the permanganate oxidation method, the method has the following advantages: the reaction condition is mild, the catalyst is cheap and efficient, the reaction is green and environment-friendly, the conversion rate of the benzoin is high,the selectivity of the benzyl is high, and good application prospect and high practical value are achieved.

Description

technical field [0001] The invention belongs to the technical field of preparing benzil, and in particular relates to a composite catalyst system that catalyzes the oxidation of benzoin to prepare benzil. Background technique [0002] Benzil, also known as diphenyl ethylene dione, biphenyl, and bibenzoyl, can be used to synthesize drug phenytoin, photosensitizers, insecticides, printing inks for food packaging, and corrosion inhibitors for low-carbon steel. Important organic synthesis intermediates and organic chemical raw materials, widely used in food, medicine, pesticide and other industries. [0003] Using benzoin as raw material, there are two methods for preparing benzil by oxidizing benzoin: one is non-catalytic oxidation. Benzoin is prepared by oxidation of benzoin with inorganic compounds, metal organic compounds, polymer compounds, etc. as oxidants, but there are problems such as large amount of oxidant, violent reaction, many by-products, and serious pollution. ...

AI Technical Summary

Problems solved by technology

Catalysis Communications (2009,10,1931–1935) reported air as oxidant, toluene as solvent, Pd / SiO 2 It is used as a catalyst to catalyze the oxidation of benzoin at 100°C to prepare benzil. The yield of benzil is 98% after reaction for 0.75h. The reaction conditions are mild, the reaction time is short, and the yield of benzil is high, but the catalyst is expensive and the reaction cost high, not conducive to industrial production

Journal of Chemical Sciences (2014, 126, 111-115) reported that at room temperature, molecular oxygen or air was used as an oxidant, p-xylene was used as a solvent, and Co(Salen) complex was used as a catalyst to catalyze the oxidation of benzoin to prepare benzil, and the reaction was 2.25h. The yield of benzil is 94%, the reaction time is short, and the catalyst efficiency is high, but the preparation of the Co(Salen) complex is cumbersome and the preparation cycle is long

Tetrahedron Letters (1999,40,7657-7659) reported air as oxidant, aqueous acetic acid as solvent, 40mol% Bi(NO 3 ) 2 and 4mol% Cu(OAc) 2 As a catalyst to catalyze the oxidation of benzoin to prepare benzil, the yield of benzil is 99% after 3 hours of reaction, the reaction conditions are mild, and the catalyst preparation is simple, but the catalyst bismuth nitrate is used in a large amount and the cost is high

Images