Succinic acid, 2-Chloro-3-hydroxy

On the other hand let us study the case of 2 chloro 3 hydroxy succinic acid which has two asymmetric carbon atoms and which are not identical. This compound exists in four stereoisomeric forms as predicted by 22 formula. The various projection formula are ... 

Utilizing a new water trap that contains a 4-A molecular sieve, Zhu et al. (2003) synthesized PBS with of 24,800 after polycondensation for 70 h with SnCl as a catalyst and dimethyl benzene as the solvent and water-removing agent. (Ishii et al. (2001) reported one-step synthesis of PBS by distannoxane-catalyzed polymerizafion of succinic acid and butanediol in a two-phase system of solvent (decalin) and molten polymer under azeotropic conditions at atmospheric pressure. When the reaction time was extended to 72 h in the presence of 0.001 mol% of l-chloro-3-hydroxy-l,l,3,3-tetrabutyldistannoxane, PBS with of 117,(XX) and of 277,(XX) was obtained. Sun et al. examined the effect of different catalysts, such as SnCl, Ti(OiPr), Ti(OBu), Sn(Oct)2, Zn(Ac)j, and p- toluenesulfonate (p-TS), on the molecular weight of solution-polymerized PBS. Among these catalysts, SnCl showed the most promising result PBS with the highest of 79,(XX) was observ after reaction for 12 h. 

In a phosphoryl chloride-polyphosphoric acid mixture the pyrido[l,2-a]-pyrimidines (78) were formed in high yield, as well as a small amount of the pyridylpyrrole derivatives (83) that were obtained from the pyridylpyrro-linones (79) through hydroxy to chloro exchange under the conditions of the ring closure. From the 6-methyl-substituted succinates (77 R = 6-Me) the pyrido[l,2- ]pyrimidines (78) and the pyridylpyrroles (83) were obtained in approximately equal amounts, in a good overall yield.132134... 

Smaller organic anions Amino acids, alkane caiiwxylic acids (formate, acetate, propionate, butyrate), chloro carboxylic acids (chloroacetate, dichloroacetate), hydroxy acids (hydroxyacetate, lactate, tartrate, citrate), glycolate, gluconate, pyruvate, dicarboxylic acids (oxalate, malonate, succinate, glutarate, fumarate, maleate), alkanesulfonic acids (methanesulfonate, ethanesulfonate). 

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See also in sourсe #XX -- [ ]

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