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 4,6-Dichloropyrimidine
1193-21-1

4,6-Dichloropyrimidine synthesis

14synthesis methods
The synthesis of 4,6-Dichloropyrimidine is as follows:Dissolve 105.5g of 4,6-diaminopyrimidine in 660.0g of 31% hydrochloric acid and pour into a 2000ml bottle to cool to -5 ° C and dropwise add 500.3g of 33% sodium nitrite. After 2 hours of reaction, HPLC detects 4,6-diamino Pyrimidine is less than 0.5%. 42.8 g of cuprous chloride and 214.0 g of 31% hydrochloric acid are prepared in a 2000 ml bottle. The diazonium salt mother liquor is added dropwise to the bottle. After the dropwise reaction, the reaction is performed at 45 ° C for 2 hours. .Extract with 400g of recovered trichloroethane (200x2 times less than new ones), combine the organic layers for distillation, control the water flush pump 5KPa, temperature 40-140 , collect 404.2g of solvent in the early 40-90 , 90-140 in the later The product was collected at a temperature of 14 ° C to obtain 146.9 g of 4,6-dichloropyrimidine. The yield was 86.4% (based on formazan hydrochloride) and the purity was 99.4%.
1193-21-1.png
-

Yield:1193-21-1 100%

Reaction Conditions:

with trichlorophosphate

Steps:

2 Example 2

Example 2 2680 g of phosphorus oxychloride were initially introduced into the reaction vessel and 980 g of 2-methyl-5-ethyl-pyridine were added, while cooling. 460 g of 4,6-dihydroxypyrimidine were then metered in over a period of 1 hour. Further reaction and working up were carried out as described in Example 1. 4,6-Dichloropyrimidine was obtained in a yield of virtually 100% and 88% by weight of the amount of amine employed was recovered.

References:

US5719285,1998,A

4,6-Dichloropyrimidine Related Search:

丰镇市| 都兰县| 鸡西市| 永宁县| 普安县| 永年县| 垦利县| 古丈县| 泽普县| 铁力市| 桃源县| 敦煌市| 北碚区| 耿马| 阜新市| 建德市| 体育| 乌鲁木齐市| 永泰县| 高淳县| 济宁市| 东至县| 绥棱县| 句容市| 高阳县| 拜城县| 班戈县| 吴川市| 仙游县| 沿河| 万山特区| 仁怀市| 安庆市| 禹州市| 侯马市| 桑日县| 广丰县| 庆元县| 陕西省| 崇阳县| 恭城|