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ChemicalBook CAS DataBase List 2-Aminothiazole-4-acetic acid
29676-71-9

2-Aminothiazole-4-acetic acid synthesis

1synthesis methods
-

Yield:29676-71-9 86.23%

Reaction Conditions:

with water;sodium hydroxide at 20 - 25; for 0.5 h;Temperature;

Steps:

1-3 Example one:
Put 25.0g of thiourea and 110ml of water into a 500mL four-necked flask, and stir for 0.5h without dissolving. Control the temperature to 20-25°C, and slowly add 54.61g ethyl 4-chloroacetoacetate dropwise. After the addition, the reaction solution gradually cleared to a homogeneous phase. After 2 hours of reaction, the liquid phase was sampled and the thiourea consumption was below 0.5%, and the reaction was stopped. Similarly, the temperature is controlled at 20-25°C, and 93.24g of 30% NaOH solution is directly added dropwise to the reaction solution. After the addition, the reaction solution is homogeneous. After the reaction took 0.5 h, the liquid phase was sampled to detect that the consumption of ethyl 2-aminothiazole-4-ethyl acetate was below 0.5%, and the reaction was stopped. Add 2.57g of activated carbon to the reaction solution, control the temperature at 20-25°C and stir for 0.5h, then suction and filter to obtain the filtrate. Control the temperature to 0-5°C, add 52.57ml of 6N HCl solution dropwise to the filtrate to pH=4.4-4.8, and after solids are deposited. After heat preservation for 0.5h, after retesting the PH value unchanged, the crude product (with water) is obtained by suction filtration. Add 100ml of water to the crude product, control the temperature at 0-5°C, beat the slurry once, and filter with suction to obtain a solid. The solid was dried under vacuum to obtain 44.34 g of pure product. The yield was 86.23%, and the purity was 99.81%.

References:

Jiangsu Hengpei Pharmaceutical Technology Co., Ltd.;Lu Fanwei;Sun Yong;Guan Xiaotian;Chen Zhe;Zhu Yongjie;Feng Yabing;Li Anpai;Wu Zhenghua;Zhang Jiaqing CN111533710, 2020, A Location in patent:Paragraph 0039-0040; 0044-0049

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