154117-91-6Relevant articles and documents
Facile aromatic nucleophilic substitution (SNAr) reactions in ionic liquids: An electrophile-nucleophile dual activation by [Omim]Br for the reaction
Zhang, Xiao,Lu, Guo-Ping,Cai, Chun
, p. 5580 - 5585 (2016/10/21)
A facile aromatic nucleophilic substitution (SNAr) reaction in recyclable [Omim]Br under relatively mild conditions has been described. An electrophile-nucleophile dual activation by [Omim]Br is also discovered based on control experiments, 1H NMR and IR spectroscopies. This chemistry provides an efficient and metal-free approach for the generation of Caryl-X (XS, N, O) bonds, many of which are significant synthetic intermediates or drugs, making this methodology attractive to both synthetic and medicinal chemistry.
Highly selective hydrolysis of chloropyrimidines to pyrimidones in 12 N hydrochloric acid
Padilla, Amphlett G.,Pearlman, Bruce A.
supporting information, p. 921 - 926 (2012/12/23)
A chromatography-free process for synthesis of 6-piperazinyl-2,4-bis- pyrrolidinylpyrimidine in isomerically pure form is described. The key step is the purification of a crude 6-chloro-2,4-bis-pyrrolidinylpyrimidine/2-chloro-4, 6-bis-pyrrolidinylpyrimidine isomer mixture (generated by reaction of 2,4,6-trichloropyrimidine with pyrrolidine) by a highly selective acid-catalyzed hydrolysis of the 2-chloro isomer to the pyrimidone. The 2-chloro isomer hydrolyzes 350 times faster than the 6-chloro isomer in 6 N HCl and 1750 times faster in 12 N HCl. To put these rate ratios in perspective, the 2-chloro isomer reacts with amines and alkoxides only ～ 10-17 times faster than does the 6-chloro isomer. A mechanistic investigation using methodological tools developed by Bunnett established that the transition state for hydrolysis of the 6-chloro isomer involves two more molecules of water (each acting as a base) than does the transition state for hydrolysis of the 2-chloro isomer. As the concentration of HCl increases from 3 N to 6 N to 12 N, there are fewer unprotonated water molecules. Thus, the transition state that involves the greater number of unprotonated water molecules (6-chloro-2,4-bis- pyrrolidinylpyrimidine) is expected to be increasingly disfavored with increasing acid concentration, as is observed. The optimized process was run successfully on production scale.
Biologically active eburnamenine derivatives, pharmaceutical compositions containing them and process for preparing same
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, (2008/06/13)
The invention relates to novel eburnamenine derivatives of formula (I): STR1 wherein R1 and R2 as well as R3 and R4, independently from each other, stand for hydrogen, C2-6 alkyl group, C2-6 alkenyl group; or a C3-10 alicyclic group involving 1 to 3 rings, and this latter group may be substituted by a C1-6 alkyl or C2-6 alkenyl group; or R1 and R2 and/or R3 and R4, together with the adjacent nitrogen atom and optionally with an additional oxygen or nitrogen atom, form a 4- to 6-membered, saturated or unsaturated cyclic group which may be substituted by a C1-6 alkyl or C2-6 alkenyl group; two of X, Y and Z are nitrogen whereas the third of them means a methine group; n is 1 or 2; W means oxygen or two hydrogen atoms; and the wavy line means α-/α-, α-/β- or β-/α- steric position, as well as their acid addition salts and solvates. The invention further relates to pharmaceutical compositions containing the above compounds as well as a process for preparing the compounds of formula (I). The compounds of formula (I) possess antioxidant effect and therefore, they are useful for inhibiting the peroxidation of lipids occurring in mammals (including human).
