16859-59-9Relevant articles and documents
Kinetics of the equilibration of 3-hydroxyphtalide and o-formylbenzoic acid. Hemiacetal breakdown with a carboxylic acid leaving group
McClelland, Robert A.,Soerensen, Poul E.
, p. 1196 - 1200 (1986)
A temperature-jump relaxation study is reported for the equilibration: 3-hydroxyphtalide (SH) o-formylbenzoate (R-) o-formylbenzoic acid (RH).A kinetic analysis is carried out in which SH and R- interconvert with catalysis in the ring opening direction by water and by added general bases.Excellent Broensted plots based upon a series of oxyacid buffer catalysts are obtained.These have slopes β for the base-catalyzed ring opening of 0.81 and α for the reverse acid-catalyzed ring closing of 0.19.A mechanism where S-, the conjugate base of SH, is a discrete intermediate can be ruled out on the basis of the Broensted values and the magnitudes of the rate constants.The lifetime of S- is estimated to lie in the range 1E-11-1E-15 s.Two mechanisms can be proposed.A fully concerted mechanism "enforced" by lifetimes less than 1E-13 s involves direct interconversion of SH and R- with no intermediate.A preassociated mechanism "enforced" by lifetimes in the 1E-11-1E-12 s range requires, in the ring closing direction, that an acid catalyst be hydrogen bonded to the carbonyl in R-.
Chiral Bicyclic Imidazole-Catalyzed Acylative Dynamic Kinetic Resolution for the Synthesis of Chiral Phthalidyl Esters
Zhou, Muxing,Gridneva, Tatiana,Zhang, Zhenfeng,He, Ende,Liu, Yangang,Zhang, Wanbin
, p. 1641 - 1645 (2020/11/30)
Utilizing a chiral bicyclic imidazole organocatalyst and adopting a continuous injection process, an alternative route has been developed for the efficient synthesis of chiral phthalidyl ester prodrugs via dynamic kinetic resolution of 3-hydroxyphthalides through enantioselective acylation (up to 99 % ee). The computational studies suggest a general base catalytic mechanism differing from the widely accepted nucleophilic catalytic mechanism. The structure analysis of the key transition states shows that the CH-π interactions and not the previously considered cation/π-π interactions between the catalyst and substrate is the dominant factor giving rise to the observed stereocontrol.
Industrial synthesis method of o-aldehyde phenyl fatty acid
-
Paragraph 0074; 0076; 0077; 0083; 0085; 0086; 0088; 0090, (2020/01/08)
The invention provides an industrial synthesis method of o-aldehyde phenyl fatty acid, which comprises the following steps: by using aromatic lactone or o-methylphenyl fatty acid as a raw material, carrying out halogenation reaction and hydrolysis to obtain the o-aldehyde phenyl fatty acid. In the method, halogen is used in the production process; however, if haloid acid or haloid salt formed byhydrolysis is directly discharged to the environment, the cost of a halogen source accounts for most of the cost of the whole process, and severe environmental pollution is caused; by means of the method, an activated halogen source can be obtained in real time by adding a specific oxidant in the reaction process, so that the closed cycle of halogen elements is realized by means of the subsequenthydrolysis process; therefore, a large amount of raw material cost is saved on the whole, environmental pollution is reduced, the product yield is high, and large-scale production is facilitated.