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]

岛国特黄毛片+A片| 久久不射| 免费看一级片| 91在线一区| 成人教育AV| 精大蛋蛋在线精品| 狠狠撸中文字幕| 久久艹免费视频| 黄色一级片亚洲永久免费| 大香蕉97在线| 欧美黄色网址| 国婷久久久| 亚洲黄色片| 欧美久久免费视频| 免费的高清黄色网址| 香草视频福利6| 国产一级婬片A片AAA| 东热激情无码N1295| 一级性爰a片视频| 日韩无码av网址| 日韩av资源在线观看| 亚洲精品性爱| 91黄色大全| 日本A片免费观看| 毛片黄色毛片| AA黄色片网站| 69无码| 黄色片子毛片视频| 最新av在线| 欧洲日本亚洲免费一级片| 中东三级片| 日韩精品中文字幕av| 毛片电影无吗| 成人AV片在线观看| 情情草1级片| 色无码网| 影音先锋琪琪色| 91亚洲婷婷| 噜噜综合日日夜夜| 91操碰国产中文字幕| 性爱AV成人一级|