Yield: 95%

Reaction Conditions:

with ammonia in isopropyl alcohol at 40 - 60;

Steps:

2 Example 2: preparation of compounds of formula II
The 32.5g formula III compound are added 170g10wt % of the isopropyl alcohol solution of ammonia, heating to 40-60°C, stirring reaction 3-5 hours, natural cooling to room temperature, filtered, collecting solid, washing with isopropyl alcohol, drying, the compound of formula II is obtained (kind of white solid) 27.2g, molar yield is 95.0%, HPLC purity of 99.0%.

References:

Shanghai Dixinuo Chemical Pharmaceutical Co., Ltd;Shanghai Desano Pharmaceutical Co., Ltd.;Li, Jinliang;Zhao, Nan;Hua, Sikai CN105272922, 2016, A Location in patent:Paragraph 0038; 0039; 0040