ChemicalBook CAS DataBase List 3-Amino-2-naphthoic acid

3-Amino-2-naphthoic acid synthesis

8synthesis methods

Product Name:3-Amino-2-naphthoic acid
CAS Number:5959-52-4
Molecular formula:C11H9NO2
Molecular Weight:187.19

92-70-6 Synthesis

92-70-6
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$10.00/10g

5959-52-4
207 suppliers
$43.20/1g

Yield:5959-52-4 87.5%

Reaction Conditions:

with ammonium hydroxide;zinc(II) chloride at 195; under 10351 - 20477 Torr; for 72 h;Autoclave;

Steps:

2 Preparation of 3-amino-2-naphthoic acid
Weigh 30g of 3-hydroxy-2-naphthoic acid,14g anhydrous zinc chloride, 110mLammonia(25-28%) placed in mechanical stirringIn a high pressure reactor,The volume of the reactor was 170 mL.The mechanical stirring speed is 700r/min, and the temperature is raised from room temperature to 195°C in 3h.The pressure reaches 1.38~2.75MPa,Then keep warm for 72h, then naturally reduce to room temperature under stirring; open the reaction kettle,Transfer all the solution in the kettle to a 500 mL three-necked flask.The reaction kettle was washed twice with 35 mL of hot water.The washing liquid was also transferred to the above three-necked flask.Then, 103 mL of concentrated hydrochloric acid was added to the three-necked flask for 1 h.The mixture was filtered with hot water, the filtrate was retained, and the filter cake was re-added to the above three-necked flask, and 90 mL of water and 5.5 mL of concentrated hydrochloric acid were added and refluxed for 1 hour, and the filtrate was combined by hot filtration.The filter cake repeats the above operation,Until the filter cake had no obvious solids. The filtrate was placed in the refrigerator and cooled overnight.Filtration on the next day, the filtrate was discarded, the filter cake was added to 300 mL of water and 40% sodium hydroxide and heated to 85 ° C to dissolve all the solids, and hot filtered to remove a little insoluble matter.Concentrated hydrochloric acid was added to the filtrate until the pH of the solution was just that the Congo red test paper did not change to blue. After suction filtration, the filtrate was discarded to obtain a yellow solid.The yellow solid was dried in a 50 ° C blast oven for 3 to 5 days.The crude 3-amino-2-naphthoic acid 24 g was weighed, and the yield was 79.6%.The above 24 g of crude 3-amino-2-naphthoic acid was recrystallized from absolute ethanol (10 g of crude 3-amino-2-naphthoic acid using 100 mL of absolute ethanol).Yellowish green 3-amino-2-naphthoic acid solid 21g,The yield is 87.5%.and the total yield of 3-amino-2-naphthoic acid was 69.6%.

References:

Huaqiao University;Cheng Lin;Sun Shengling;Zhou Xiaheng;Wang Delian CN108558901, 2018, A Location in patent:Paragraph 0055; 0056; 0057

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