47 results about "P-nitrobenzyl alcohol" patented technology

The invention relates to a method for synthesizing mono-4-nitrobenzyl malonate. The method comprises the steps of adding para-nitrobenzyl alcohol, malonic acid or malonate and a reaction solvent to a reaction flask at a mol ratio of 1: (1-10): (10-50); heating in a water bath until being balanced; adding lipase and a water absorbent to the reaction flask at a mol ratio of (0.1-1): (0-100) with the para-nitrobenzyl alcohol; controlling temperature at 30-50 DEG C, reacting for 10-48 hours, filtering to remove the lipase to obtain a reaction solution, and carrying out reduced pressure distilling on the reaction solution to remove the solvent, to obtain reaction residue; adding a mixing solution of an organic solvent and a salt solution to the reaction residue, stirring and layering, acidifying an obtained water phase, carrying out suction filtering and drying to obtain the mono-4-nitrobenzyl malonate. The method is easily available in raw materials, few in reaction step, moderate in reaction condition, few in side product, and simple and convenient to operate; the method, because the adopted organic solvent can be recycled, is low in environmental impact, simple in post-treatment, relatively high in production purity and yield, and suitable for industrial production.

A high selectivity synthesis method of p-nitrobenzaldehyde comprises the following steps: firstly, adding p-nitrotoluene, peroxycarbonate used as catalyst and dichloroethane used as solvent in a reactor, dropping bromine at 40-50 DEG C under stirring, then reacting at 50-60 DEG C to ensure that the color of bromine fades, adding hydrogen peroxide to react at 60-70 DEG C for no less than 4 hours and prepare 4-nitrobenzyl bormide; and secondly, adding 25-35% sodium carbonate solution to hydrolyze at 80-95 DEG C and generate p-nitrobenzyl alcohol, standing to separate, and finally using oxygen as oxidant to react for no less than 25 hours in the presence of catalyst triphenylphosphine metal salt organic complex under the conditions that the temperature is 50-90 DEG C and the pressure 5.1*10<5>-1.0*10<6>. The overall yield of the method is no less than 70%, the product purity is no less than 99% and the dosage of bromine is 50-60% of the theoretical amount.

The invention discloses a cost-saving preparation method of p-nitrobenzyl alcohol. The key points of the technical scheme are as follows: according to the cost-saving preparation method of the p-nitrobenzyl alcohol, p-nitrotoluene is taken as a starting raw material and reacts with chlorine gas to obtain p-nitrobenzyl chloride, and then the p-nitrobenzyl chloride is hydrolyzed in an alkaline solution to obtain p-nitrobenzyl alcohol. Compared with the prior art, the cost-saving preparation method of the p-nitrobenzyl alcohol has the following beneficial effects: the reaction system is simple and the raw material is cheap and easily available; the preparation cost is low and no hazardous waste is generated, so that the preparation method accords with the green production ideal; the cost-saving preparation method is simple in process, simple and convenient to operate, short in reaction time, high in efficiency and suitable for large-scale production.

The present invention relates to the technical field of electrolytes, in particular to a high-conductivity and high-sparking electrolyte for an aluminum electrolytic capacitor and a preparation method therefor. The electrolyte comprises the following raw materials in parts by weight: 4.5-6.5 parts of ammonium sebacate, 1.5-2.5 parts of ammonium hydrogen azelate, 1.5-2.5 parts of ammonium pentaborate, 13-17 parts of a sparking boosting agent, 1.5-2.5 parts of ammonium dodecanedioate, 0.2-0.3 part of ammonium hypophosphite, 0.3-0.7 part of p-nitrobenzyl alcohol and 60-85 parts of glycol. The electrolyte is prepared by means of interaction among the raw materials and by strictly controlling a weight proportion of the raw materials; the sparking voltage of the prepared electrolyte can reach 490 V and the conductivity rate of the prepared electrolyte can reach 2.4 ms / cm; and the electrolyte has good electrochemical properties, has the advantages of high conductivity and high sparking voltage, and can be applied to manufacturing of the aluminum electrolytic capacitors.

The invention provides a process for synthesizing 4-Nitrobenzyl chloroformate, which comprises reacting trichloromethyl chloroformate or bis(trichloromethyl)carbonate with p-nitrobenzyl alcohol at -40-20 deg C under the action of acid-binding agent, finally carrying out post-treatment to obtain the outcome yield.

The invention provides a method for preparing p-nitrobenzyl alcohol malonate monoester by double-enzyme catalysis, comprising the steps of: using 2-cyanoacetic acid-(4-nitrophenyl) methyl ester as a substrate, using It is obtained through combined catalysis of nitrilase derived from Alcaligenes faecalis and amidase derived from Alcaligenes faecalis. The method of the invention has high product yield, few by-products, mild reaction conditions and little environmental pollution, and is suitable for industrialized production.

The invention provides protected meropenem synthesized under simple conditions. In the invention, a compound (I) is reacted with mono-4-nitrobenzyl malonic acid ester and magnesium chloride to form a compound (II) product; the compound (II) is diazotized to form a compound (III) product; the compound (III) is dehydrated by methanesulfonic acid to obtain a compound (IV) product; the compound (IV) is cyclized to form a compound (V) product, and 4-dimethylaminopyridine, diphenyl chlorophosphate and N,N-diisopropylethylamine are added in turn to participate in reactions to form a product (VI) product; and N,N-diisopropylethylamine and (2S,4S)-2-dimethylaminocarbonyl-4-thio-1-(p-nitrobenzyloxycarbonyl)pyrrolidine are added to participate in a reaction to obtain a compound (VII) product. The method has the advantages that: the cost as well as 'waste gas, liquid and solid' are reduced, the operation is convenient, and the post-treatment is simple; and the total molar yield of the six-step reactions is more than or equal to 74 percent, so the method is easy to industrialize.

The present invention relates to the technical field of electrolytes, in particular to a high-sparking and anti-lightning electrolyte for an aluminum electrolytic capacitor and a preparation method therefor. The electrolyte comprises the following raw materials in parts by weight: 1.5-2.5 parts of ammonium dodecanedioate, 0.8-1.2 parts of ammonium sebacate, 5-9 parts of sorbitol, 4-6 parts of boracic acid, 4-6 parts of diethylene glycol monobutyl ether, 1-2 parts of polyvinyl alcohol, 0.4-0.6 part of p-nitrobenzyl alcohol, 0.1-0.3 part of ammonium hypophosphite, 6-10 parts of ethylene glycol nano silica sol and 60-80 parts of glycol. The electrolyte is prepared by means of interaction among the raw materials and by strictly controlling a weight proportion of the raw materials; the sparking voltage of the prepared electrolyte can reach 590 V and the conductivity rate of the prepared electrolyte can reach 0.5 ms / cm; and the electrolyte has good electrochemical properties, has the advantages of high sparking voltage, lightning resistance and the like, and can be applied to manufacturing of the aluminum electrolytic capacitors.