Method for preparing o-nitroacetophenone by oxidizing o-nitroethylbenzene through biomimetic-catalysis oxygen

Abstract

The invention discloses a method for preparing o-nitroacetophenone by oxidizing o-nitroethylbenzene through biomimetic-catalysis oxygen, comprising the following steps of: taking the o-nitroacetophenone as a raw material, selecting any or one combination of 1-30ppm of mononuclear metal porphyrin and mu-oxygen-binuclear metal porphyrin as catalysts, introducing oxygen at the flowing speed of 10-60mL / min; carrying out an initiating reaction at a temperature of 150-200DEG C; and then reacting at a temperature of 80-130DEG C for 10-18h to obtain the o-nitroacetophenone. By adopting a mode of rapid initiation at high temperature and reaction at low temperature, the method ensures that the initiating time for reaction is excessively short, greatly shortens the reaction time, improves the reaction efficiency, reduces energy source consumption, reduces the operation fees and enhances the reaction safety.

Description

technical field [0001] The invention relates to a method for preparing aromatic ketones, in particular to a method for preparing o-nitroacetophenone by biomimetic catalytic oxygen oxidation of o-nitroethylbenzene. Background technique [0002] O-nitroacetophenone is an important intermediate in organic synthesis, widely used in the synthesis of medicines, pesticides, dyes, flavors and fragrances, perfumes, etc. The preparation method of o-nitroacetophenone mainly contains acetophenone nitration method at present, 1-(2-nitrophenyl) ethanol oxidation method and o-nitroethylbenzene oxidation method etc., wherein o-nitroethylbenzene oxidation method and It is divided into chemical oxidation method and molecular oxygen oxidation method. Oxygen is used as an oxidant that is cheap and easy to get, clean and pollution-free, and has good atom economy. The method for preparing o-nitroacetophenone by directly oxidizing o-nitroethylbenzene with oxygen is relatively Other methods have s...

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Problems solved by technology

[0005] (1) In this method, highly toxic chromium trioxide is used as a catalyst, and the consumption is very large (30200ppm), so that a large amount of waste water or waste residue containing chromium trioxide is discharged into the environment, which will cause extremely serious damage to the environment, and even will endanger human health

Therefore, used chromium trioxide must be separated and recovered, and the separated recovery needs to consume a large amount of energy;

[0006] (2) The method uses chromium trioxide catalyst with extremely low activity, so that the yield is only 14% after 28 hours of reaction. The reaction time is so long and the yield is so low, which not only consumes a large amount of energy and resources, but also produces Excessive operating costs and extremely low production efficiency

And too high reaction temperature not only consumes a lot of energy, but also can significantly reduce the safety of production;

[0008] (4) the aftertreatment process of this method adopts sodium carbonate aqueous solution to wash, and its result will produce a large amount of saline waste water, and saline waste water is one of the waste water that is the most difficult to carry out biochemical treatment in the waste water treatment process, can cause serious environmental pollution;

[0009] (5) The method adopts the mode of vacuum distillation to purify o-nitroacetophenone, because of the boiling point (112.5~113.5 ℃ (2mmHg)) of o-nitroacetophenone is very high, in the process of vacuum distillation not only needs a lot of High temperature and vacuum, high energy consumption, equipment investment and operating costs will increase exponentially, and production safety cannot be guaranteed;

Not only because of its toxicity and harmfulness, it may cause serious environmental pollution, but also because of the increase of energy consumption due to the recovery of solvents, which greatly increases operating costs and production costs;

[0020] (3) Due to the use of high-pressure reaction conditions, equipment investment and operating costs are doubled, and energy consumption is extremely high, especially making production potentially dangerous and greatly reducing safety;

[0021] (4) The use of loaded or polymerized metalloporphyrins results in high energy consumption, high discharge of three wastes, complex processes, and increased costs due to the complex preparation process

In addition, due to the large amount of catalyst used (480ppm), it must be separated and recovered after use, and the cost of separating and recovering the catalyst is high, energy consumption is large, and three wastes are discharged.

In addition, because the reaction using supported or polymerized metalloporphyrins is a heterogeneous reaction, the high catalytic activity of metalloporphyrins cannot be well reflected.

[0022] (5) The induction time of the reaction is too long (up to 3h), thus prolonging the entire reaction time, resulting in serious waste of energy and increase in operating costs

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