| Identification | More | [Name]
4-Hydroxy-3,5-dimethylbenzoic acid | [CAS]
4919-37-3 | [Synonyms]
3,5-DIMETHYL-4-HYDROXYBENZOIC ACID
4-HYDROXY-3,5-DIMETHYLBENZOIC ACID
RARECHEM AL BO 0868
Benzoic acid, 4-hydroxy-3,5-dimethyl-
4-Hydroxy-3,5-Dimethylbenzoic | [EINECS(EC#)]
256-495-9 | [Molecular Formula]
C9H10O3 | [MDL Number]
MFCD00016536 | [Molecular Weight]
166.17 | [MOL File]
4919-37-3.mol |
| Safety Data | Back Directory | [Hazard Codes ]
Xi | [Risk Statements ]
R36/37/38:Irritating to eyes, respiratory system and skin . | [Safety Statements ]
S37/39:Wear suitable gloves and eye/face protection .
S26:In case of contact with eyes, rinse immediately with plenty of water and seek medical advice . | [RTECS ]
DG8997500 | [HS Code ]
29182900 |
| Hazard Information | Back Directory | [Chemical Properties]
off-white to light pink or light beige crystalline | [Uses]
4-hydroxy-3,5-dimethylbenzoic acid is widely used as a reagent for potent TTR amyloidogenesis inhibitors. It plays an important role as an intermediate in agrochemicals and dyestuffs. It is also used in the preparation of mexiletine derivatives. | [Synthesis]
(1) In a 500 mL three-necked flask, p-hydroxybenzoic acid (138 g, 1 mmol) and methanol (160 g, 5 mmol) were added, followed by solid acid catalyst (50 g). The mixture was stirred until homogeneous. The reaction flask was placed in an ultrasonic reactor and fitted with a reflux condensing unit. The reaction temperature was adjusted to 40-60°C and the ultrasonic power was set to 500 W for 1-3 hours. During the reaction, the color of the reaction solution gradually changed from white to yellow and finally to orange-red. The reaction process was monitored by high performance liquid chromatography (HPLC), and the reaction was judged to be complete when the residual amount of p-hydroxybenzoic acid was less than 5%. After stopping the reaction, the solid acid catalyst was removed by filtration (the catalyst can be recycled for subsequent reactions). The filtrate was allowed to crystallize at 5-10°C for 6-10 hours, after which the crystals were collected by filtration. The crystals were dried at 50-60°C for 6 h. The intermediate 4-hydroxy-3,5-dimethylbenzoic acid (141 g, 85% yield) was obtained by HPLC with impurity content of less than 0.1% in the product. | [References]
[1] Patent: CN106588576, 2017, A. Location in patent: Paragraph 0074-0080 |
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