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 Nicotinamide
98-92-0

Nicotinamide synthesis

14synthesis methods
-

Yield:98-92-0 96%

Reaction Conditions:

Stage #1: 2-chloropyridine-3-carboxylic acid N,N-dimethylamidewith sodium thiosulfate * 6H2O in lithium hydroxide monohydrate at 77; for 6 h;
Stage #2: with chlorine in lithium hydroxide monohydrate at 0; for 1 h;

Steps:

1.1-1.3; 2.1-2.3; 3.1-3.3 A preparation method of nicotinamide, the steps are as follows:

(1) in 500mL four-necked flask, drop into 60g 2-chloro-N,N-dimethylnicotinamide and 100mL water, be warming up to 77 , drip the sodium thiosulfate aqueous solution that 200g concentration is 45wt%, drop home After the end, the reaction was incubated at 77° C. for 6 hours, and sampling was performed for analysis. When the content of 2-chloro-N,N-dimethylnicotinamide was less than 0.3%, the temperature was lowered to prepare theAqueous solution of sodium dimethylnicotinamide sulfonate;(2) in a 1000mL four-necked flask, at 0°C, add the dimethylnicotinamide sulfonic acid sodium salt aqueous solution described in step (1) into 200mL of water, and feed chlorine gas (at 0.587g) into the water while adding. /min rate, the introduction time is 3.5 hours), then after the reaction was incubated at 0 °C for 1 h, dichloromethane was added to obtain a dichloromethane mother liquor, which wasThe dichloromethane mother liquor is used after washing with water;(3) the extraction mother liquor after the washing described in step (2) is cooled to 5 and then feeds 17g (1mol) of ammonia gas, adds 100mL of water after the completion of the ammonia gas flow, drips hydrochloric acid to adjust the pH of the system after pH=2, cools down to -5°C, then centrifuged, washed with clean water, and then vacuum-dried to obtain 96.97 g of the product with a yield of 96% and a purity of 98.5%.That is, the nicotinamide is prepared.

References:

CN114940662,2022,A Location in patent:Paragraph 0027-0041

Nicotinamide Related Search:

乌鲁木齐市| 台东县| 许昌市| 淮南市| 林口县| 布尔津县| 本溪| 贵阳市| 常山县| 昆明市| 民和| 宾阳县| 大厂| 垣曲县| 太原市| 宁国市| 中方县| 八宿县| 延安市| 大姚县| 宕昌县| 南华县| 宜州市| 册亨县| 临桂县| 清流县| 阿拉善右旗| 西乡县| 衡山县| 潜山县| 邓州市| 北辰区| 长宁县| 平阳县| 武安市| 普兰县| 孟津县| 秦皇岛市| 涪陵区| 信丰县| 浑源县|