天堂网亚洲,天天操天天搞,91视频高清,菠萝蜜视频在线观看入口,美女视频性感美女视频,95丝袜美女视频国产,超高清美女视频图片

Welcome to chemicalbook!
Chinese English Japanese Germany Korea
400-158-6606
Try our best to find the right business for you.
Do not miss inquiry messages Please log in to view all inquiry messages.

Welcome back!

ChemicalBook CAS DataBase List 2,4-DINITROBENZOIC ACID
610-30-0

2,4-DINITROBENZOIC ACID synthesis

8synthesis methods
-

Yield:610-30-0 96.3%

Reaction Conditions:

with dihydrogen peroxide in water at 60; for 0.5 h;Sonication;Temperature;

Steps:

3 Example 3 A method for preparing 2,4-difluorobenzoic acid includes the following steps:
(1) After mixing tetraethylorthosilicate and triethylamine, adding tetrabutyl titanate in ethanol solution to obtain a sol; (2) mixing the silica sol and tetrapropylammonium hydroxide aqueous solution under ultrasonic conditions, adding tetrabutyl titanate in ethanol, continuing the ultrasonic stirring for 1 hour, and then placing it under the condition of 90°C for 24 hours, It was added to the sol prepared in Step 1, after reaction at 120 ° C for 54h, cooled to room temperature, the product was filtered, washed, dried and calcined to obtain TS-1 molecular sieve; (3) After mixing 2,4-dinitrotoluene with water, the prepared TS-1 molecular sieve is added and mixed uniformly, and the temperature is controlled at 60° C., H2O2 is added dropwise with stirring, and the reaction is continued after the dropwise addition is completed. 30min, after filtration, vacuum distillation, recrystallization with ethanol to obtain 2,4-dinitrobenzoic acid; (4) After mixing 2,4-dinitrobenzoic acid and TMSO, heating to a temperature of 120° C., adding sodium fluoride, stirring and refluxing for 8 hours, cooling to room temperature, removing TMSO under reduced pressure, and then using steam. After distillation, the fractions were collected and allowed to stand for 48 hours, the upper layer material was removed, and the lower oily material was cooled and crystallized, followed by recrystallization to obtain 2,4-difluorobenzoic acid. The molar ratio of tetraethyl orthosilicate, triethylamine, and tetrabutyl titanate in step (1) is 40:3:1; silica sol, tetrapropylammonium hydroxide, tetrabutyl titanate in step (2). 50:5:1; the molar concentration of tetrabutyl titanate in the ethanol solution of tetrabutyl titanate in step (1) and step (2) is 6 mol/L. In step (3), the mass ratio of 2,4-dinitrotoluene to TS-1 molecular sieve is 3:2; the molar ratio of 2,4-dinitrotoluene to H2O2 is 1:2. The molar ratio of 2,4-dinitrobenzoic acid to sodium fluoride in step (4) was 1:2.3. The yield of 2,4-difluorobenzoic acid prepared was 96.3%

References:

Suzhou Aitike Pharmaceutical Chemical Co., Ltd.;Hu Haiwei CN107954853, 2018, A Location in patent:Paragraph 0020-0069

FullText

2,4-DINITROBENZOIC ACID Related Search: