54903-85-4Relevant academic research and scientific papers
Synthesis and biological evaluation of aroylguanidines related to amiloride as inhibitors of the human platelet Na+/H+ exchanger
Laeckmann, Didier,Rogister, Fran?oise,Dejardin, Jean-Victor,Prosperi-Meys, Christelle,Géczy, Joseph,Delarge, Jacques,Masereel, Bernard
, p. 1793 - 1804 (2007/10/03)
Pyridine and benzene bioisosteres of amiloride were synthesized and evaluated for their inhibitory potency against the sodium-hydrogen exchanger (NHE) involved in intracellular pH regulation. The inhibition of NHE was determined by using the platelet swelling assay (PSA) in which the swelling of human platelets was induced by their incubation in an acid buffer (pH 6.7). Additionally, the inhibitory potency of the most active compounds was assessed by measuring the inhibition of the EIPA-sensitive 22Na+ uptake (UIA) by human platelets after intracellular acidosis. The results indicated that several benzene derivatives and compounds bearing an carbonylguanidine moiety in the meta position of the pyridine nitrogen were much more potent than amiloride (PSA:IC50=43.5 μM; UIA:IC50=100.1 μM), but less than EIPA, a pyrazine NHE inhibitor (PSA:IC50=0.08 μM; UIA:IC50=0.5 μM). In both biological assays (2-amino-5-bromo-pyridine-3-carbonyl)guanidine (32) was the most active molecule (PSA:IC50=0.8 μM, UIA:IC50=0.8 μM). Our investigations demonstrated that the replacement of the pyrazine ring of amiloride by a pyridine or a phenyl ring improved the NHE inhibitory potency (phenyl >pyridine >pyrazine).
NEW DEVELOPMENTS IN THE SYNTHESIS OF LOWER FLUORINATED PYRIDINES VIA DIAZOTIZATION-FLUORINATION OF AMINOPYRIDINES IN ANHYDROUS HYDROGEN FLUORIDE
Boudakian, Max M.
, p. 497 - 506 (2007/10/02)
The isolation and stabilization of elusive 4-fluoropyridine as the hydrochloride salt (54percent yield) from fluorodediazoniation of 4-aminopyridine in anhydrous hydrogen fluoride (AHF) is described.Unlike the low yields (0-13percent) recently reported from the chlorodediazoniation of 2,6-diaminopyridine and 3-halo-2,6-diaminopyridine, fluorodediazoniation gave high yields (49-62percent) of the corresponding 2,6-difluoropyridines.In contrast, benzene analogs, i.e. m-phenylenediamine and 4-chloro-m-phenylenediamine, form only tars under similar fluorination conditions.Vicinal aminohalopyridines, e.g. 3-amino-2-chloropyridine and 2-amino-3,5-dichloropyridine give the corresponding fluorohalopyridine in 49-89percent yield.Again, the benzene analogs, i.e. o-chloroaniline and 2,4-dichloroaniline, resist fluorination.
A Convenient Synthesis of 2,3,5,6-Tetrahalogenopyridines and of 3,5-Bis(alkylthio)pyridines from 2,6-Diaminopyridine
Chen, Ted K.,Flowers, William T.
, p. 1139 - 1140 (2007/10/02)
Controlled chlorination of 2,6-diaminopyridine (1) affords 2,6-diamino-3,5-dichloropyridine (2a) which is then bis(diazotised) to give 2,3,5,6-tetrachloropyridine (3a); similarly prepared are other 2,3,5,6-tetra(chloro/bromo) pyridines and 2,6-dichloro-3,5-bis(thiocyanato)pyridine (3h), from which 3,5-bis(alkylthio)pyridines are easily obtained.
