在线看AV的网址,青青青草成人自拍,深喉口爆一区二区三区,5月天黄色视频,精品福利在草草

Hydrogen fluoride-pyridine

0

category
Product
CAS No.
32001-55-1;62778-11-4
Purity
≥99%

Product Details

Name: Hydrogen fluoride-pyridine/PPHF/Pyridine Poly(hydrogen fluoride)/Olah's Reagent

CAS number : 32001-55-1; The 62778-11-4

Molecular formula:C5H5N.nHF(where n≥1)

Purity:≥99%

Appearance: Light yellow to reddish brown transparent liquid

Boiling point: 50℃/1mmHg

Free HF%: 65-70%

Packing: 1kg/ bottle, 25kg/ barrel, 50kg/ barrel

Use: fluorinated reagent

_________________________________________________________________________________________________________

Hydrogen fluoride-pyridine complex (PPHF) is an improvement on the application form and mode of hydrogen fluoride reagent, which can be simply regarded as hydrogen fluoride with a higher boiling point. The PPHF obtained by Olah reagent preparation method can stabilize the temperature of HF emission to about 55 ℃. Compared with anhydrous hydrogen fluoride, PPHF can probably be considered to have the same reaction, the reaction activity is slightly reduced, the selectivity is greatly increased, and the stereochemistry of the product may be different.

PPHF has been widely used in the fluorination ring opening reaction of oxygen - and nitrogen-containing ternary rings. The ring-opening reaction of epoxide fluoridation that can be accomplished by anhydrous hydrogen fluoride can also be accomplished by PPHF [2], and it has been found that PPHF can obtain better results in some reactions [3]. Usually the reaction can be carried out under very mild conditions with very high stereoselectivity and satisfactory yields (Equation 1)[4,5]. The stereochemistry of the fluorinated ring-opening product of the nitrogen-containing ternary ring is just complementary to the anhydrous hydrogen fluoride reagent (Equation 2)[6]

亚洲天堂av黄色电影| 日韩不卡人妻| 在线能看的huang网| 亚洲色国产| 双飞性爱视频| 色色亚洲A V| 亚洲先锋97| 九色超碰导航在线观看| 小说图片三级页面| 色a在线| 亚洲黄页| 亚洲有码在线| A V黄色电影在线| 久久总站| av在线小电影| 欧洲一级片蜜乳AV| 日本一级黄A片| www.二区三区视频| 超碰91久久网| 五月天色色婷婷| 国产精品视频八区| 成人日韩无码| AA黄色片| 能在线看的av| 美国成人黄色一级免费| 免费无码视频成人看片| 六月天色色网| 亚洲激情性爱网| 色色综合站| a爰片在线看免费| 黄色网精品一区| 免费超碰av| av性爱网站| av 大香蕉| 日本无码影片| 亚洲高清无砖专区| 大香蕉伊人在线观看视频| 二三四五区视频| 日本乱妇伦A片免费看| 日韩无码波多野结衣| 日韩无码人妻一区二区|