Sulfonation and sulfation in the reactions of the chloro- and dichlorophenols, 3-fluorophenol and (2,3-, 2,4- and 3,4-dichlorophenoxy)acetic acid with concentrated aqueous sulfuric acid and sulfur trioxide
作者:Peter de Wit、Hans Cerfontain
DOI:10.1002/recl.19881070303
日期:——
The chloro- and dichlorophenols have been sulfonated with sulfuric acid and with SO3 in aprotic solvents. In the sulfonations with concentrated aqueous sulfuric acid, the sulfonic acid isomer distribution is determined mainly by the ortho- and para-directing and activating effect of the hydroxy substituent; this is also the determining factor in the aprotic sulfonations using up to 1.0 equiv of SO3
Sulfonation of chloro- and dichloroanisoles with concentrated aqueous sulfuric acid and sulfur trioxide. Demethylation of chloroanisolesulfonic acids in sulfuric acid systems
作者:Peter de Wit、Hans Cerfontain
DOI:10.1002/recl.19881070605
日期:——
The nine chloro- and dichloroanisoles have been sulfonated with sulfuric acid. The observed sulfonic acid isomer distributions are determined mainly by the ortho- and para- directing effect of the methoxy substituent. In the reaction with sulfuric acid, the initially formed chloro- and dichloroanisolesulfonic acids are demethylated to give the corresponding phenolsulfonic acids. Demethylation occurs
Structure−Reactivity Correlations in the Dissociative Hydrolysis of 2‘,4‘-Dinitrophenyl 4-Hydroxy-X-benzenesulfonates
作者:Giorgio Cevasco、Sergio Thea
DOI:10.1021/jo961024k
日期:1996.1.1
The hydrolysis reactions of several title esters in water at 60 degrees C follow the rate law k(obs) = (k(a) + k(b)[OH(-)])/(1 + a(H)/K(a)), where K(a) is the ionization constant of the hydroxy group of the ester and k(b) is the second-order rate constant for the S(N)2(S) attack of hydroxide ion on the ionized ester. Hammett and Brønsted correlations are consistent with a previous proposal that the
On the intermediacy of phenyl hydrogen sulfates in the sulfonation of phenols. Sulfonation of phenol, anisole, methyl phenyl sulfate, the 2-halogenophenols, a series of phenyl methanesulfonates together with 2,6-dimethylaniline and its N-methylsulfonyl de
作者:Peter de Wit、Alex F. Woldhuis、Hans Cerfontain
DOI:10.1002/recl.19881071204
日期:——
The sulfonation of methylphenylsulfate (4) with concentrated aqueous sulfuric acid at 25°C yields the 4-sulfonic acid. This initial product then decomposes to give phenol-4-sulfonic acid, which is subsequently sulfonated to phenol-2,4-disulfonic acid. From the first-order-rate coefficients obtained for sulfonation of phenylmethanesulfonate (3) and (4) in 93.2% H2SO4, for which acid concentration
在25℃下用浓硫酸水溶液磺化甲基苯基硫酸酯(4),得到4-磺酸。然后该初始产物分解得到苯酚-4-磺酸,随后将其磺化为苯酚-2,4-二磺酸。从在93.2%H 2 SO 4中将甲磺酸苯基酯(3)和(4)磺化所获得的一级系数,对于磺酸浓度为H 2 S 2 O 7的酸浓度,其σp +值OSO 2 Me和OSO 2已确定OMe取代基分别为0.40和0.46。2-氯苯基(10)和2-甲基苯基甲磺酸盐(14)在2.0 °C下在硝基甲烷中用2.0当量的SO 3磺化产生4-磺酸作为排他的产物,而2-甲氧基苯基甲烷磺酸盐(13),在相同条件下,仅形成5-磺酸。
[EN] GLUCAGON ANTAGONISTS/INVERSE AGONISTS<br/>[FR] ANTAGONISTES/AGONISTES INVERSES DU GLUCAGON
申请人:NOVO NORDISK AS
公开号:WO1999001423A1
公开(公告)日:1999-01-14
Non-peptide compounds comprising a central hydrazide motif and methods for the synthesis thereof. The compounds act to antagonize the action of the glucagon peptide hormone.