Methyl Anthranilate CAS 134-20-3

The preparation method of methyl anthranilate comprises the following steps:

1. 25% Ammoniacal liquor of 937kg10 ℃ is put into amidation reactor, 1000kg phthalic anhydride is dropped in the amidation reactor, and ammoniacal liquor and phthalic anhydride react in the environment below 30 ℃ to generate o-formamide benzoic acid ammonium, react Time 2.5h. The 25% ammoniacal liquor that actually participates in the amidation reaction is 892.3kg, and 937kg of 25% ammoniacal liquor is added for the amidation reaction to be more complete.
2. After the amidation reaction, put into the sodium hydroxide solution of 879kg30% in the amidation reactor, o-formamide benzoic acid ammonium and sodium hydroxide generation displacement reaction generate sodium o-formamide benzoate, then the amidation reactor The temperature inside rises to 50°C, and the ammonia molecules in the mixed solution are evaporated, and the evaporated ammonia gas is led by the induced draft fan to the two-stage series water absorption tower for water absorption to obtain ammonia water, and the ammonia water is sent to the ammonia water storage tank, and then to the ammonia water storage tank Add liquid ammonia inside to make 25% ammonia water for reuse.
3. Put the solution in the amidation reactor into the esterification reactor, put into the methanol solution of 1561kg75% and the sodium hypochlorite solution of 3451kg14% in the reactor, keep the temperature in the esterification reactor to be 10 DEG C, react A paste-like methyl anthranilate was generated, and the reaction time was 3 hours. After the reaction, the temperature in the esterification reactor was raised to 50°C. Add 1000kg hot water in the esterification reactor after the dissolving of pasty methyl anthranilate.
4. Send the solution in the esterification reaction kettle into the methyl ester settling tank and let it stand for separation. The solution in the upper layer is pumped into the methanol recovery process, and the solution in the lower layer is filtered by a jet vacuum pump to obtain the filtrate. Stand still and separate, pump the solution in the upper layer into the methanol recovery process, put the filtrate in the lower layer into the distillation pot, and carry out distillation in an environment with a pressure of 2.00Kpa and a temperature of 135.5°C to obtain a finished product.

The solution sent to the methanol recovery process is pumped into the methanol rectification tower. Using the different boiling points of the components in the solution, the methanol in the solution is evaporated first, and the methanol vapor is condensed to obtain a methanol solution. The remaining solution is cooled and crystallized. Send it to the centrifuge, and after centrifugation, it can be sold as industrial salt.

A kind of one-step method produces the production technique of methyl anthranilate, specifically comprises the following steps:

1. Add 18.2g of N-chlorophthalimide, 6.4g of methanol and 40g of water into a three-necked flask, then lower the temperature to below 0°C, and stir to make a slurry.
2. Add 16.2g of 30% sodium hydroxide aqueous solution dropwise, after dropping, keep the temperature below 0°C and stir for 20 minutes.
3. After raising the temperature to 50-80° C. for one hour, the temperature was naturally lowered, and the layers were separated for ten hours, and the product 13.8 g of methyl anthranilate was obtained in the lower layer. The product purity is 99.8%, and the yield is 91.4%.

1. First add ammonia water with a ratio of 0.115 to 0.135 parts (relative to phthalic anhydride) in the amidation reaction kettle, start stirring, add 1 part of phthalic anhydride within one minute, and add a ratio of 0.27 parts (relative to phthalic anhydride) Part to 0.90 parts of liquid caustic soda, to make it undergo amidation reaction, and always ensure that the pH value is greater than 7 during the production of amidation liquid. When the pH value reaches 8.5, stop adding liquid caustic soda, after fully stirring, the amidated liquid that generates is discharged ammonia.
2. Pump the amidation solution after exhausting ammonia into the esterification reaction kettle, add 0.216 parts to 1 part of methanol in proportion (relative to phthalic anhydride), cool down to below -15°C, and then add 4 parts below zero ~5 parts of sodium hypochlorite solution with a mass concentration of 11% are subjected to Hofmann degradation reaction to generate methyl anthranilate solution.
3. Put the generated methyl anthranilate solution into the filter through the pump, filter, and the filtered solution enters the methyl ester crystallization tank, start stirring, cool down to below 24°C, and make the methyl anthranilate solution The crystallization of methyl ester is separated out, obtains solid methyl ester through filtration.
4. Pump the filtered filtrate into the alkali removal kettle, cool down to below 0°C, and precipitate water alkali (sodium carbonate decahydrate).
5. The filtrate after filtering the water alkali (sodium carbonate decahydrate) is pumped into the distillation tower, evaporated, and the obtained gas phase recovers methanol.
6. The distillation raffinate at the bottom of the distillation tower reclaims anthranilic acid.
7. The waste water containing less than 3% salt after recovering anthranilic acid is treated for waste water.