Study On The Synthetic Technology Of O-Nitrophenylacetic Acid

At present, the nitrotoluene and its derivatives develop fast and are very competitive inthe world because of its low price. The synthesized proportion of o-nitrotoluene, m-nitrotolueneand p-nitrotoluene is 60:4:36 in the synthetic process ,and the synthetic proportion ofo-nitrotoluene is the largest while the demand of p-nitrotoluen is great. Which causes the excessof o-nitrotoluene. The o-nitrophenylacetic acid is a kind of organic intermediate with wideusage,butthetraditional syntheticmaterials(o-nitrophenylacetonitrile)are noteasilyobtained.So studying the synthetic thechnology of the o-nitrophenylacetic acid using the o-nitrotolueneasmaterialshas greatpracticalvalue.Using the sodium phenolate as catalyzer, the o-nitrophenylacetic acid is synthesized bythe o-nitrotoluene reacting with carbon dioxide, then the o-nitrophenylacetic acid is obtainedthrough acidification and purification that method was been studied by this paper . In addition,the possible side effects are analyzed . Combined with condensation oxidation synthesis ofo-Nitrophenylacetic acid method, method with ethanol as solvent,sodium ethylate as catalystprocess improvements are proposed and explored tentatively.Studies the method to synthesize the o-nitrophenylacetic acid, that is the o-nitrotolueneand diethyl oxalate are condensed under the catalysis of sodium ethoxide, and then theo-nitrophenylacetic acid is obtained through many processes, such as hydrolysis and oxidationand extraction and acidification . Through the orthogonal test find the best synthetic conditionis that the proportion of o-nitrotoluene, sodium ethoxide and diethyl oxalate is 1:1.2:1.28, thecondensation reaction time is 3h and temperature is 45℃, and the oxidation reactiontemperature is below 20℃. And validated test, the product yield can reach 89.2%, purityreach 98.70%.