Preparation method for biphenyltetracarboxylic dianhydride mixture
The invention relates to a preparation method for a biphenyltetracarboxylic dianhydride mixture. The preparation method comprises the following steps: with phthalic acid as a starting raw material, carrying out an electrophilic substitution reaction so as to produce a phthalic acid derivative; then subjecting the derivative to esterification so as to produce phthalate; further catalyzing phthalate and carrying out a coupling reaction so as to produce a biphenyl tetraformate mixture; and finally, successively carrying out saponification and acidification so as to produce the product biphenyltetracarboxylic dianhydride mixture. The method provided by the invention uses cheap and easily phthalic acid as the starting raw material and is a novel low-cost easily-operatable environment-friendly production method for biphenyltetracarboxylic dianhydride; moreover, isomeric compounds of all the biphenyltetracarboxylic dianhydride are synthesized at one time in the invention, so efficiency is improved and the cost is reduced.
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Paragraph 0030; 0031
(2016/10/09)
Azabicyclic compounds for the treatment of disease
The invention provides compounds of Formula I: wherein Azabicyclo is W is a six-membered heterocyclic ring system having 1-2 nitrogen atoms or a 10-membered bicyclic-six-six-fused-ring system having up to two nitrogen atoms within either or both rings, provided that no nitrogen is at a bridge of the bicyclic-six-six-fused-ring system, and further having 1-2 substitutents independently selected from R3. These compounds may be in the form of pharmaceutical salts or compositions, may be in pure enantiomeric form or racemic mixtures, and are useful in pharmaceuticals to treat diseases or conditions in which α7 is known to be involved.
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Page 42
(2010/02/06)
The Diels-Alder approach to musk odor type arenes
The readily accessible 2-halogeno-1-trimethylsilyloxy-1,3-butadienes react smoothly with dimethyl acetylenedicarboxylate to afford 4-halophthalic esters. One of these cycloadducts was subsequently converted into heterocyclic analogues of phantolide like musk fragrances.
Shi,Cottens,Shiba,Schlosser
p. 10569 - 10574
(2007/10/02)
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