Background and overview[1-2]
2-Hydroxybenzoic acid monoammonium salt is also called ammonium salicylate. Ammonium salicylate is an ammonium salt of organic acid generated by the reaction of salicylic acid and ammonia gas or ammonia water, and has good water solubility. The properties of ammonium salicylate are different from those of salicylic acid. It does not sublime and has certain high temperature resistance. Unlike salicylic acid, which will decarboxylate and decompose at high temperatures and generate phenol.
Apply[1-2]
Application 1,
2-Hydroxybenzoic acid monoammonium salt can be used to prepare o-hydroxybenzonitrile. As a pharmaceutical intermediate, o-hydroxybenzonitrile can be used in the preparation of bunilol, a drug for the treatment of hypertension and angina. As a pesticide intermediate, o-hydroxybenzonitrile can be used in the preparation of the methoxyacrylate fungicide azoxystrobin. . In addition, o-hydroxybenzonitrile, as an important intermediate, can also be used in the synthesis of a variety of spices and liquid crystal materials.
The aqueous solution containing 2-hydroxybenzoic acid monoammonium salt is evaporated under normal pressure or reduced pressure to obtain 2-hydroxybenzoic acid monoammonium salt solid; the 2-hydroxybenzoic acid monoammonium salt is used to neutralize urea in an organic solvent After reacting in the presence of a catalyst to generate a mixture containing o-hydroxybenzonitrile, it is then filtered or centrifuged, distilled under reduced pressure, crystallized or recrystallized to obtain a mixture that can be widely used in many fields such as medicine, pesticides, spices, and liquid crystal materials. O-hydroxybenzonitrile, a fine organic synthesis intermediate. When o-hydroxybenzonitrile is prepared by this method, it can not only reduce the equipment requirements for the production of o-hydroxybenzonitrile and the production cost of o-hydroxybenzonitrile, but also improve the utilization rate of the raw material salicylic acid and reduce the cost of using existing processes. Reduce the “three wastes” emissions when preparing o-hydroxybenzonitrile and improve the quality of the product.
Application 2,
2-Hydroxybenzoic acid monoammonium salt can be used to prepare salicylamide. The chemical name of salicylamide is o-hydroxybenzamide. It is a reliable antipyretic and analgesic drug and is used clinically. Headache, fever, joint pain and rheumatism; at the same time, it is an important fine chemical intermediate and is widely used in medicine, pesticides, spices, dyes, synthetic auxiliaries and other fields.
The method for preparing salicylamide from 2-hydroxybenzoic acid monoammonium salt is as follows: add 2-hydroxybenzoic acid monoammonium salt and acidic catalyst into the reactor at a mass ratio of (0.2~40):1. , add water to prepare an ammonium salicylate solution with a saturation of 80%; finally, salicylamide is obtained after dehydration and separation.
References
[1] [Chinese invention] CN201010238014.9 Preparation method of salicylamide
[2] [Chinese invention] CN201110058467.8 A method for preparing o-hydroxybenzonitrile using ammonium salicylate as raw material
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