US 12,304,892 B2
Method for preparation of Carsalam
Xingbang Lin, Zhongshan (CN); and Ji Zhou, Guangzhou (CN)
Assigned to LONZA GUANGZHOU PHARMACEUTICAL LTD., Guangzhou (CN)
Appl. No. 17/603,107
Filed by LONZA GUANGZHOU PHARMACEUTICAL LTD., Guangzhou (CN)
PCT Filed May 18, 2020, PCT No. PCT/EP2020/063843
§ 371(c)(1), (2) Date Oct. 12, 2021,
PCT Pub. No. WO2020/234245, PCT Pub. Date Nov. 26, 2020.
Claims priority of application No. PCT/CN2019/087542 (WO), filed on May 20, 2019; and application No. 19180140 (EP), filed on Jun. 14, 2019.
Prior Publication US 2022/0194906 A1, Jun. 23, 2022
Int. Cl. C07D 265/26 (2006.01); C07D 265/20 (2006.01)
CPC C07D 265/26 (2013.01) 16 Claims
 
1. A method for the preparation of compound of formula (3)

OG Complex Work Unit Chemistry
with two subsequent reactions REAC1 and REAC2;
in the first reaction REAC1 salicylamide is reacted with diethylcarbonate in the presence of an alkali ethoxide to provide compound of formula (3-X)

OG Complex Work Unit Chemistry
in the second reaction REAC2 compound of formula (3-X) obtained from REAC1 is reacted with a Bronsted acid to provide compound of formula (3);
X is Na or K;
the alkali ethoxide is NaOEt or KOEt.