Yield:1026201-52-4 89.8%

Reaction Conditions:

with sodium hydroxide in tetrahydrofuran;water at 40; for 3 h;

Steps:

46.2 Step 2: Synthesis of 5-bromoimidazo[1,2-a]pyridine-2-carboxylic acid (Intermediate 46B)
Ethyl 5-bromoimidazo[1,2-a]pyridine-2-carboxylate (10g, 37.3mmol),Sodium hydroxide (3g, 74.6mmol) was placed in a single-necked flask, THF (200mL) and water (200mL) were added, and the reaction was heated to 40°C for 3 hours. The THF was removed under reduced pressure, and the remaining solution was adjusted to pH 5 with concentrated hydrochloric acid. Then, the precipitated solid was filtered and the filter cake was dried to obtain 8.00 g of the title product as a white solid. Yield: 89.8%.

References:

China Pharmaceutical Research And Development Center Co., Ltd.;Yin Huijun;Yan Xu;Han Yachao;Shi Jizhou;Dong Liuxin;Xin Piming;Ren Guang;Mi Zhen;Lu Jiawei;Li Hao;Ma Jing CN111320624, 2020, A Location in patent:Paragraph 0495-0497; 0500-0501

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