3984-22-3Relevant articles and documents
Efficient synthesis of α-branched purine-based acyclic nucleosides: Scopes and limitations of the method
Dra?ínsky, Martin,Frydrych, Jan,Janeba, Zlatko,Slavětínská, Lenka Po?tová
, (2020/10/02)
An efficient route to acylated acyclic nucleosides containing a branched hemiaminal ether moiety is reported via three-component alkylation of N-heterocycle (purine nucleobase) with acetal (cyclic or acyclic, variously branched) and anhydride (preferentially acetic anhydride). The procedure employs cheap and easily available acetals, acetic anhydride, and trimethylsilyl trifluoromethanesulfonate (TMSOTf). The multi-component reaction is carried out in acetonitrile at room temperature for 15 min and provides moderate to high yields (up to 88%) of diverse acyclonucleosides branched at the aliphatic side chain. The procedure exhibits a broad substrate scope of N-heterocycles and acetals, and, in the case of purine derivatives, also excellent regioselectivity, giving almost exclusively N-9 isomers.
Method of preparing optically active alpha -amino acids and alpha -amino acid derivatives
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, (2008/06/13)
PCT No. PCT/EP96/03984 Sec. 371 Date Apr. 30, 1998 Sec. 102(e) Date Apr. 30, 1998 PCT Filed Sep. 11, 1996 PCT Pub. No. WO97/10203 PCT Pub. Date Mar. 20, 1997The invention relates to a new process for the preparation of optically active amino acids and amino acid derivatives of the general formula (I), wherein *, X and R1 to R4 have the meaning given in the description. Starting from commercially obtainable (-)-menthol or (+)-menthol, the enantiomerically pure compounds of the formula (I) are obtained in high yields. The method is particularly suitable for the preparation of sterically demanding amino acids and amino acid derivatives.
Process for the production of 2-vinyl-1,3-dioxolane
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, (2008/06/13)
Process for the production of 2-vinyl-1,3-dioxolane reacting acrolein with ethylene glycol in the presence of a solid, acidic catalyst and recovery of the reaction mixture. Selectivity may be increased in comparison with known prior art processes by performing the reaction in the presence of a solid acidic catalyst at a temperature of below 50° C.; the reaction mixture, from which the catalyst has been removed, is treated by extraction using an organic solvent which substantially does not dissolve ethylene glycol and has a boiling point of above 130° C.; the two phases obtained on extraction are treated for recovery by distillation and recovered educts and the organic solvent are recycled.
