Name | 2,4-Difluorobenzoic acid |
Synonyms | 2,4-DFBA NSC 10312 RARECHEM AL BO 0245 4-Difluorobenzoic acid 2,4-Difluorobenzoic acid 2,4-Difluorobenzonicacid Benzoic acid, 2,4-difluoro- |
CAS | 1583-58-0 |
EINECS | 216-430-9 |
InChIKey | NJYBIFYEWYWYAN-UHFFFAOYSA-N |
Molecular Formula | C7H4F2O2 |
Molar Mass | 158.1 |
Density | 1.3486 (estimate) |
Melting Point | 188-190 °C (lit.) |
Boling Point | 239.5±20.0 °C(Predicted) |
Water Solubility | SOLUBLE |
Solubility | DMSO (Slightly), Ethyl Acetate (Slightly), Methanol (Slightly) |
Appearance | White crystal |
Color | Pale Orange to Light Pink |
BRN | 973355 |
pKa | 3.21±0.10(Predicted) |
Storage Condition | Sealed in dry,Room Temperature |
MDL | MFCD00011670 |
Physical and Chemical Properties | Chemical Properties White Powder |
Use | Uses pharmaceutical and liquid crystal intermediates. |
Hazard Symbols | Xi - Irritant |
Risk Codes | 36/37/38 - Irritating to eyes, respiratory system and skin. |
Safety Description | S26 - In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. S37/39 - Wear suitable gloves and eye/face protection |
WGK Germany | 3 |
HS Code | 29163990 |
Hazard Class | IRRITANT |
Downstream Products | 2,4-Difluorobenzotrifluoride 2,4-DIFLUORO-5-NITROBENZOIC ACID 3-bromo-2,6-difluorobenzoic acid 4-FLUORO-2-METHOXYBENZAMIDE METHYL 4-FLUORO-2-HYDROXYBENZOATE |
storage conditions | Sealed in dry,Room Temperature |
acidity coefficient (pKa) | 3.21±0.10(Predicted) |
water solubility | SOLUBLE |
BRN | 973355 |
InChIKey | NJYBIFYEWYWYAN-UHFFFAOYSA-N |
NIST chemical information | 2,4-Difluorobenzoic acid(1583-58-0) |
EPA chemical information | Benzoic acid, 2,4-difluoro- (1583-58-0) |
WGK Germany | 3 |
Hazard Note | Irritant |
HazardClass | IRRITANT |
customs code | 29163990 |
application
2, 4-difluorobenzoic acid is an important drug and pesticide intermediate, such as 2, 4-difluorobenzoic acid is mainly used to synthesize antifungal drugs fluconazole, voriconazole and drug pesticide intermediate 4-fluorosalicylic acid, drug intermediate 3, 5-difluoroaniline, etc. 2, 4-difluorobenzoic acid can also be used in liquid crystal materials, which has the advantages of high value and good market prospects.
Preparation
Add 2, 4-dinitrotoluene and water to the reaction vessel, adjust the pH value to 7, stir and heat to 75°C. Potassium permanganate, magnesium sulfate and phase transfer catalyst were added in batches. After adding, continue to stir and react at constant temperature for 3 hours. Filter while hot and wash the filter cake with hot water. Merge the filtrate, acidify with 35% hydrochloric acid to pH 2-3, there are a large number of white precipitates after the crystals are completely precipitated, filtered, washed, recrystallized, and dried to obtain white crystals as 2,4-dinitrobenzoic acid. The ratio of 2, 4-dinitrotoluene to potassium permanganate is 2.4:1. The product yield of this step is 90.7%.
add N,N-dimethylmethylphthalamide into the reaction container, heat to 100~110 ℃, preheat for 0.5~1h. Add dried anhydrous potassium fluoride under stirring and keep the temperature preheated for 0.5-1h. After that, 2, 4-dinitrobenzoic acid and hexyltrimethylammonium bromide were quickly added to the reaction vessel at one time, and the heating was continued to 120 ℃, the temperature was maintained and the stirring reaction was continued. After 7h of reflux reaction, the solvent is recovered by distillation, and then the reaction liquid is distilled with steam. The collected fraction is a white emulsion. After standing for a period of time, the oily target fraction basically sinks to the bottom, the white clear liquid on the upper part is poured, and the oil is cooled to precipitate white crystals to obtain a crude product; the crude product is recrystallized, Suction filtration, washing, and drying to obtain white crystals of 2,4-difluorobenzoic acid. The ratio of the amount of 2, 4-dinitrobenzoic acid to potassium fluoride is 2.7:1. The product yield of this step is 72.4%.
application | 2,4-difluorobenzoic acid is an important drug and pesticide intermediate, such as 2,4-difluorobenzoic acid is mainly used to synthesize antifungal drugs fluconazole, voriconazole and drug pesticide intermediate 4-fluorosalicylic acid, drug intermediate 3, 5-difluoroaniline, etc. 2, 4-difluorobenzoic acid can also be used in liquid crystal materials, which has the advantages of high value and good market prospects. |
preparation | add 2, 4-dinitrotoluene and water to the reaction vessel, adjust the pH value to 7, stir and heat to 75 ℃. Potassium permanganate, magnesium sulfate and phase transfer catalyst were added in batches. After adding, continue to stir and react at constant temperature for 3 hours. Filter while hot and wash the filter cake with hot water. Merge the filtrate, acidify with 35% hydrochloric acid to pH 2-3, and a large number of white precipitates are filtered after the crystals are completely precipitated, washed, recrystallized, and dried to obtain a white crystal of 2,4-dinitrobenzoic acid. The ratio of 2, 4-dinitrotoluene to potassium permanganate is 2.4:1. The product yield of this step is 90.7%. add N,N-dimethylmethylphthalamide into the reaction container, heat to 100~110 ℃, preheat for 0.5~1h. Add dried anhydrous potassium fluoride under stirring and keep the temperature preheated for 0.5-1h. After that, 2, 4-dinitrobenzoic acid and hexadecyltrimethylammonium bromide were quickly added to the reaction vessel at one time, and the heating was continued to 120 ℃, the temperature was maintained and the stirring reaction was continued. After 7h of reflux reaction, the solvent is recovered by distillation, and then the reaction liquid is distilled with steam. The collected fraction is a white emulsion. After standing for a period of time, the oily target fraction basically sinks to the bottom, the white clear liquid on the upper part is poured, and the oil is cooled to precipitate white crystals to obtain a crude product; the crude product is recrystallized, Suction filtration, washing, and drying to obtain white crystals of 2,4-difluorobenzoic acid. The ratio of 2, 4-dinitrobenzoic acid to potassium fluoride is 2.7:1. The product yield of this step is 72.4%. |
chemical properties | white powder |
use | pharmaceutical and liquid crystal intermediates. |
NIST chemical information | The information is: webbook.nist.gov provides (external link) |
EPA chemical information | The information is: offered by ofmpub.epa.gov (external link) |