一二三四区视频,亚洲少妇熟女色,日本久热无码视频网,欧美国产日韩大尺度,亚洲a视频,久久少妇一区二区,日韩999无码视频,刺激久久久久久久,啊啊啊啊不要啊在线

Welcome to chemicalbook!
Chinese English Japanese Germany Korea
010-86108875
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 Cefdinir
91832-40-5

Cefdinir synthesis

2synthesis methods
79349-82-9 Synthesis
7-AVCA

79349-82-9
246 suppliers
$10.00/250mg

143183-03-3 Synthesis
(Benzothiazol-2-yl)-(Z)-2-trityloxyimino-2-(2-aminothiazole-4-yl)-thioacetate

143183-03-3
108 suppliers
$680.00/1g

-

Yield:91832-40-5 85.8%

Reaction Conditions:

Stage #1:(6R,7R)-7-amino-3-vinyl-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid;S-(2-benzothiazolyl) 2-(2-aminothiazol-4-yl)-2(Z)-trityloxyiminothioacetate with triethylamine in N,N-dimethyl acetamide at 15 - 20; for 4 h;
Stage #2: with hydrogenchloride;methoxybenzene in dichloromethane;N,N-dimethyl acetamide at -15 - -10; for 2 h;

Steps:

1 Example 1
In a dry reaction flask, add 30g 7-AVCA, 85g cefdinir side chain active ester and 100 ml dimethylacetamide. Control temperature at 15 °C -20 °C. Add dropwise 30g triethylamine. Stir the reaction for 4h. The reaction completely becomes clear. After the reaction is complete, add 250 ml dichloromethane. Lower the temperature to -15 °C - -10 °C. Add 50 ml anisole. Place dry hydrogen chloride gas. After about 2h, HPLC measured end point of the reaction, the reaction after the end of the, through N2Away excess hydrogen chloride gas in the system. Then add 100 ml H2O, dropping 10% of Na2CO3Solution, adjusting the pH value of 5.5 - 6.0, the temperature does not exceed 5 °C, layered. The aqueous phase is then added to 100 ml CH2Cl2Extraction, layered, add aqueous 3g decolorized with active carbon, the decolorization 1h after filtering, adding 500 ml water, for 2 mol/L hydrochloric acid to adjust the pH value to 2.2 - 2.4, temperature control 20 °C -25 °C, nourishing crystal 2h after filtering, washing, alcohol washing, drying, to obtain cefdinir 45g, yield 85.8%, the purity is ≥ 99%.

References:

China Union Chempharma (Suzhou) Co., Ltd.;Suzhou No.3 Pharmaceutical Factory Co., Ltd.;Zhou, Zijin;Zhang, Bo;Huang, Junhao;Chen, Feng;Luo, Xinzu;Yang, Long;Hu, Liyong;Wang, Lei CN106279207, 2017, A Location in patent:Paragraph 0030; 0031; 0032

FullText

Cefdinir Related Search:

平潭县| 勐海县| 茶陵县| 盘锦市| 云龙县| 海阳市| 呼和浩特市| 乳山市| 沙湾县| 金溪县| 容城县| 新郑市| 和林格尔县| 土默特右旗| 汉源县| 邹平县| 绥滨县| 高陵县| 莱阳市| 鹿邑县| 邳州市| 隆林| 遂溪县| 余姚市| 宜昌市| 合山市| 额尔古纳市| 图木舒克市| 永善县| 平湖市| 四会市| 怀化市| 秦皇岛市| 元谋县| 工布江达县| 万年县| 南丰县| 龙井市| 开化县| 仁化县| 金昌市|