39834-49-6Relevant articles and documents
KMnO4-catalyzed chemoselective deprotection of acetate and controllable deacetylation-oxidation in one pot
Gurawa, Aakanksha,Kumar, Manoj,Rao, Dodla S.,Kashyap, Sudhir
, p. 16702 - 16707 (2020/10/27)
A novel and efficient protocol for chemoselective deacetylation under ambient conditions was developed using catalytic KMnO4. The stoichiometric use of KMnO4 highlighted the dual role of a heterogeneous oxidant enabling direct access to aromatic aldehydes in one-pot sequential deacetylation-oxidation. The reaction employed an alternative solvent system and allowed the clean transformation of benzyl acetate to sensitive aldehyde in a single step while preventing over-oxidation to acids. Use of inexpensive and readily accessible KMnO4 as an environmentally benign reagent and the ease of the reaction operation were particularly attractive, and enabled the controlled oxidation and facile cleavage of acetate in a preceding step. This journal is
METHOD OF PREPARING (3R,5R)-7-(2-(4-FLUOROPHENYL)-5-ISOPROPYL-3-PHENYL-4-((4-HYDROXYMETHYLPHENYLAMINO)CARBONYL)-PYRROL-1-YL)-3,5-DIHYDROXY-HEPTANOIC ACID HEMI CALCIUM SALT, INTERMEDIATES USED THEREIN, AND METHOD OF PREPARING THE INTERMEDIATES
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Paragraph 0309-0313; 0321-0325, (2019/10/22)
The present invention provides a method for manufacturing a (3r,5r)-7-(2-(4-fluorophenyl)-5-isopropyl-3-phenyl-4-((4-hydroxymethylphenylamino)carbonyl)-pyrrol-1-yl)-3,5-dihydroxy-heptanoic acid hemi-calcium salt, an intermediate thereof, and a manufacturing method thereof. According to the present invention, the manufacturing method is performed in a convergent synthesis method of individually synthesizing each main structural part of the (3r,5r)-7-(2-(4-fluorophenyl)-5-isopropyl-3-phenyl-4-((4-hydroxymethylphenylamino)carbonyl)-pyrrol-1-yl)-3,5-dihydroxy-heptanoic acid hemi-calcium salt and coupling the synthesized main structural parts. Accordingly, a flexible material can be easily controlled and manufacturing time can be reduced, thereby increasing productivity of a compound and yield of the final compound.COPYRIGHT KIPO 2019
Highly efficient protection of alcohols as trityl ethers under solvent-free conditions, and recovery catalyzed by reusable nanoporous MCM-41-SO3H
Gholamzadeh, Zeynab,Naimi-Jamal, Mohammad Reza,Maleki, Ali
, p. 994 - 1001 (2015/01/09)
An efficient method was developed for the protection of alcohols as trityl ethers using triphenylmethanol in the presence of nanoporous MCM-41-SO3H as a heterogeneous catalyst under solvent-free ball-milling at room temperature. Low catalyst loading, high efficiency, reusability are among the advantages of this new solvent-free and environmentally friendly method. The deprotection of the produced trityl ethers was also efficiently achieved using the same catalyst in wet acetonitrile.
Zinc chloride homogeneous catalysis in the tritylation of hydroxyl- and amide-bearing molecules
Maltese, Maurizio,Vergari, Maria Cecilia,Donzello, Maria Pia
supporting information; experimental part, p. 483 - 487 (2011/03/18)
A tritylation protocol based on the transfer of the triphenylmethylcarbenium ion from trityl acetate to substrates having hydroxyls, in the presence of catalytic amounts of ZnCl2, is described. The advantages of this method are broad scope, mild conditions, and easy handling. The comparison with the procedure based on the use of equimolar mixture of TrCl and ZnCl2 in the presence of TEA shows that comparable results are obtained. However, only this method allows reactions of secondary or benzylic alcohols such as oxidation or formation of symmetric ethers to be suppressed. Both procedures are successfully extended to simple and substituted amides. Irrespective of its low solubility in acetonitrile, even asparagine can be directly tritylated on its amide group.
