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:

西吉县| 兴文县| 神农架林区| 隆化县| 五峰| 乌恰县| 靖远县| 大城县| 大城县| 井冈山市| 平陆县| 平邑县| 邓州市| 英超| 贵溪市| 镇康县| 淮南市| 哈密市| 吉木萨尔县| 晋城| 福建省| 安陆市| 巩留县| 湄潭县| 息烽县| 临高县| 凤凰县| 永福县| 周口市| 来凤县| 巴彦县| 肃南| 宜君县| 平阴县| 曲阳县| 崇阳县| 汪清县| 屏山县| 建瓯市| 资源县| 靖远县|