Reference of 25983-13-5, Because a catalyst decreases the height of the energy barrier, its presence increases the reaction rates of both the forward and the reverse reactions by the same amount.25983-13-5, Name is 6,7-Dichloroquinoxaline-2,3(1H,4H)-dione, molecular formula is C8H4Cl2N2O2. In a article£¬once mentioned of 25983-13-5
A cephalosporin nucleus lorraine ester intermediates preparation method (by machine translation)
The invention provides a cephalosporin nucleus lorraine ester intermediates preparation method, comprises the following steps: the 3 – hydroxy cephalosporin with acid activating reagent with the organic solvent in the presence of reaction, the activated intermediate is obtained; the activating reagent is paratoluene sulfonyl chloride, benzene sulfonyl chloride, 4 – nitrobenzene sulfonyl chloride, anhydride or trifluoromethanesulfonic anhydride three fluorine vinegar; to the activated intermediate with 4 – (4 – pyridyl) – 2 – mercapto thiazole reaction, the reaction is carried out with the quaternizing reagent, to obtain the pyridine salt; and then deprotected, get the cephalosporin nucleus lorraine ester intermediate. Compared with the prior art, the invention to the toluene sulfonyl chloride, benzene sulfonyl chloride, 4 – nitrobenzene sulfonyl chloride, fluorine vinegar anhydride or trifluoromethanesulfonic anhydride three alternative a chloride to reduce the poisonous the use of the materials, so that the safety of the reaction is improved, while at the same time, due to the steric hindrance of the activating group increase, reducing the delta – 3 isomer the probability of generating, improves the purity and yield of the reaction product. (by machine translation)
A reaction mechanism is the microscopic path by which reactants are transformed into products. Each step is an elementary reaction. In my other articles, you can also check out more blogs about 25983-13-5
Reference£º
Quinoxaline – Wikipedia,
Quinoxaline | C8H6N1844 | ChemSpider