19078-71-8Relevant articles and documents
Synthesis of enantiomerically enriched-bromonitriles from amino acids
Tka, Najeh,Kraem, Jamil,Hassine, Bechir Ben
, p. 735 - 743 (2013/01/15)
Two methods were investigated for the preparation of six chiral-bromonitriles with different optic purities. The nitrous deamination of amino acids gives-bromoacids, which react with chlorosulfonyl isocyanate followed by triethylamine to afford-bromonitriles with moderate enantiomeric excess. However, the dehydration of corresponding-bromoamids using thionyl chloride gives-bromonitriles with good enantiomeric excess up to 94%. The use of phosphoryl chloride instead of thionyl chloride results in more than 30% racemization as determined by high-performance liquid chromatograpic analysis.
Imidazo[1,2-b]pyridazines, novel nucleus with potent and broad spectrum activity against human picornaviruses: Design, synthesis, and biological evaluation
Hamdouchi, Chafiq,Sanchez-Martinez, Concha,Gruber, Joseph,Del Prado, Miriam,Lopez, Javier,Rubio, Almudena,Heinz, Beverly A.
, p. 4333 - 4341 (2007/10/03)
A novel structural class of picornavirus inhibitors comprising an imidazo[1,2-b]pyridazine nucleus was discovered. 2-Aminoimidazo[1,2-b]pyridazines (6d, (E/Z)-7b, (E)-7d, (Z)-7d, (E/ Z)-8b, (E)-10b, (E)-13a, (Z)-13a, (E)-13b, (Z)-13b, (E)-13c, and (Z)-13c) were designed and synthesized in an effort to identify potent broad spectrum antirhinoviral agents. A practical synthetic route to this chemical scaffold has been developed. The target compounds were evaluated in a plaque reduction assay and in a cytopathic effect assay. Our preliminary SAR studies highlight the minimum structural features required for antirhinovirus activity. Our data suggest that the nature of the linker between the phenyl and the imidazopyridazine moieties has a significant influence on the activity of these compounds. Oximes are slightly better than vinyl carboxamides at this position. The oximes are the most potent analogues against human rhinovirus 14 (HRV-14), and at the concentrations evaluated, no apparent cellular toxicity is noted. Furthermore, the E geometry appears to be a key element for activity; the Z isomer leads to a considerable loss in potency. Of particular interest, analogue 7b exhibits potent broad-spectrum antirhinoviral and antienteroviral activity when evaluated against a panel of seven additional rhino- and enteroviruses. The chemistry and the biological evaluations are discussed.
2-amino-3-substituted-6-[(E)-1-phenyl-2-(N- methylcarbamoyl)vinyl]imidazo-[1,2-a]pyridines as a novel class of inhibitors of human rhinovirus: Stereospecific synthesis and antiviral activity
Hamdouchi, Chafiq,De Blas, Jesús,Del Prado, Mirian,Gruber, Joseph,Heinz, Beverly A.,Vance, Lori
, p. 50 - 59 (2007/10/03)
A series of 2-amino-3-substituted-6-[(E)-1-phenyl-2-(N- methylcarbamoyl)vinyl]imidazo[1,2-a]-pyridines 1a-i, structurally related to Enviroxime and its analogous benzimidazoles, was designed and prepared for testing as antirhinovirus agents. The imidazo ring in this class of compounds was constructed starting from the aminopyridine after tosylation and subsequent treatment with the appropriate acetamides. The key steps in the synthesis include the development and use of a new Horner-Emmons reagent for the direct incorporation of methyl vinylcarboxamide. The reaction was stereospecific in the substrates 5a-f leading exclusively to the desired E- isomer and avoiding the use of reverse-phase preparative HPLC for the separation of both possible isomers before antiviral activity evaluation. The isopropylsulfonyl group, known as the best substituent at the 1-position in the benzimidazole SAR in terms of activity, was introduced in this new series of imidazo[1,2-a]pyridines via halogen-metal exchange and subsequent treatment with isopropyl isopropanethiolsulfonate. Compounds 1a-i were evaluated in plaque reduction assay and in a cytopathic effect assay. Compounds 1b-d,h exhibited a strong antirhinovirus activity, and no apparent cellular toxicity was visible. The substitution at the 3-position was required for activity. Surprisingly the isopropylsulfonyl in this family of compounds did not enhance the activity as in the case of benzimidazoles. Instead, compound 1i was 4 times less active than its phenyl and sulfide partners. The chemistry as well as the biological evaluation are discussed.
