52070-18-5Relevant articles and documents
'Green' synthesis of 2-substituted 6-hydroxy-[3H]-pyrimidin-4-ones and 4,6-dichloropyrimidines: Improved strategies and mechanistic study
Opitz, Andreas,Sulger, Werner,Daltrozzo, Ewald,Koch, Rainer
, p. 814 - 824 (2015/05/20)
An improved route to 2-substituted 6-hydroxy-[3H]-pyrimidin-4-ones 4 and to 2-substituted 4,6-dichloropyrimidines 5 is reported. Without using highly toxic reactants, compounds 4 can be prepared conveniently in a one pot synthesis on a one mol scale with average yields up to 80%. 4,6-Dichloropyrimidines 5, which are usually prepared in small quantities, are synthesized with average yields of 80%, using up to 80g of starting material. The mechanism of the chlorination of 4 is investigated computationally for the first time. The results suggest that the chlorination with phosphoryl chloride occurs in an alternating phosphorylation-chlorination manner (pathway 1) which is preferred over a sequence which starts with two phosphorylations. The investigated 4,6-dichloropyrimidines described herein form strong complexes with dichlorophosphoric acid but weak complexes with hydrochloric acid (generated during workup). These latter complexes explain the necessity of using aqueous sodium carbonate during the working up. In order to prevent possible formation of pyrimidinium salts between intermediates or the final dichloropyrimidines and unreacted hydroxypyrimidone, the latter could be deactivated with a strong acid such as dichlorophosphoric acid, thus allowing chlorination but prohibiting salt formation. Because of its general applicability to all nitrogen heterocycle chlorinations with phosphoryl chloride, the proposed route to dichloropyrimidines without solvent or side products, using less toxic reactants, is of general synthetic interest.
One-flask synthesis of 1,3,5-trisubstituted 1,2,4-triazoles from nitriles and hydrazonoyl chlorides via 1,3-dipolar cycloaddition
Wang, Li-Ya,Tsai, Henry J.,Lin, Hui-Yi,Kaneko, Kimiyoshi,Cheng, Fen-Ying,Shih, Hsin-Siao,Wong, Fung Fuh,Huang, Jiann-Jyh
, p. 14215 - 14220 (2014/04/17)
A one-flask strategy for the synthesis of 1,3,5-trisubstituted 1,2,4-triazoles 4a-s and 8a and b from nitriles 5a-i with N-arylhydrazonoyl hydrochlorides 3a-h and 7a and b under basic conditions was developed. The reaction provided the desired 1,2,4-triazoles in moderate to excellent yields (56-98%), and was applicable to aliphatic and aromatic nitriles as well as N-phenylhydrazonoyl hydrochlorides bearing ester and acetyl functionalities. A 1,3-dipolar cycloaddition between imidate and nitrilimine generated from the respective nitrile and N-arylhydrazonoyl chloride in one flask was proposed for the new transformation.
Reverse-benzamidine antimalarial agents: Design, synthesis, and biological evaluation
Berger, Olivier,Wein, Sharon,Duckert, Jean-Frederic,Maynadier, Marjorie,Fangour, Siham El,Escale, Roger,Durand, Thierry,Vial, Henri,Vo-Hoang, Yen
scheme or table, p. 5815 - 5817 (2010/11/17)
In the frame of the development of bis-cationic choline analogs, the RSA of bis-N-alkylamidines were studied and a new series of reverse-benzamidine derivatives was designed. Contrary to the lipophilicity, the basicity of alkylamidine compounds directly influences their antimalarial potencies.
