ChemicalBook CAS DataBase List 2,5-Dimethylphenylacetic acid

2,5-Dimethylphenylacetic acid synthesis

11synthesis methods

Product Name:2,5-Dimethylphenylacetic acid
CAS Number:13612-34-5
Molecular formula:C10H12O2
Molecular Weight:164.2

6972-51-6 Synthesis

6972-51-6
61 suppliers
$55.00/5 g

13612-34-5
239 suppliers
$5.00/1g

Yield:13612-34-5 97.65%

Reaction Conditions:

Stage #1:2-(2,5-dimethylphenyl)ethan-1-ol with sodium hypochlorite;2,2,6,6-Tetramethyl-1-piperidinyloxy free radical in water;ethyl acetate at 5 - 20; for 1 h;
Stage #2: with hydrogenchloride in water;ethyl acetate; pH=5 at 27 - 33;
Stage #3: with sodium chlorite in water;ethyl acetate for 3.5 h;Temperature;

Steps:

1-3 Example 1:
In a 250mL four-neck bottle,80 mL of ethyl acetate was added at room temperature, 18.3 g of 2,5-dimethylphenylethanol (molecular weight 150.22, 121.82 mmol, 1.0 eq) obtained in the previous step, 381.22 mg TEMPO (molecular weight 156.24, 2.44 mmol, 0.02 eq). Cool down to 5 °C, slowly add 98.93 g mass fraction 11% sodium hypochlorite solution (molecular weight 74.44, 146.19 mmol, 1.2 eq), Add dropwise for about half an hour, and stir for 30 minutes. Adjust the pH of the aqueous phase to 5 with 30% hydrochloric acid. The temperature of the reaction solution was then raised to 27 to 33 °C. Slowly add aqueous sodium chlorite solution (Sodium chlorite is 80% pure, molecular weight 90.44, 146.19 mmol, 1.2eq, 16.53g sodium chlorite is dissolved in 49.6g of water to make a 25% solution). Finish dripping in about half an hour, and keep stirring for 3h after dripping. Allow the layers to stand and separate. The lower aqueous phase was extracted with 40 mL of ethyl acetate. The combined organic phases were concentrated to dryness under negative pressure. Obtained 19.45 g of white solid (molecular weight 164.2, theoretically 19.46 g). The purity was 96.9% by HPLC, which was 2,5-dimethylphenylacetic acid, and the yield was 97.65%.

References:

Jiangsu Zhongqi Technology Co., Ltd.;Zhang Pu;Bu Long;Wu Yaojun;Hou Yuanchang CN110305009, 2019, A Location in patent:Paragraph 0037-0051

201230-82-2 Synthesis