ChemInform Abstract: Synthesis and Protonation Behavior of 26‐Membered Oxaaza and Polyaza Macrocycles Containing Two Heteroaromatic Units of 3,5‐Disubstituted Pyrazole or 1‐Benzylpyrazole. A Potentiometric and ¹H and ¹³C NMR Study.

Abstract

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

In vitro leishmanicidal activity of pyrazole-containing polyamine macrocycles which inhibit the Fe-SOD enzyme of Leishmania infantum and Leishmania braziliensis species

“…After stirring overnight at room temperature, the intermediate Schiff base separated as a white solid that was crystallized from EtOH (405 mg, 72%, mp 161–162 °C) (lit. 160–162 °C; Arán et al 1999). A stirred suspension of the above Schiff base (394 mg, 0·7 m m ) in EtOH (20 mL) was reduced by stepwise addition of solid sodium borohydride (303 mg, 8·0 m m ).…”

“…1,5-diamino-3-octylazapentane is not commercial and was obtained from 1,5-diamino-3-azapentane (Miranda et al 2004). 1 H -pyrazole-3,5-dicarbaldehyde and 1-benzyl-1 H -pyrazole-3,5-dicarbaldehyde were obtained from 3,5-dimethyl-1 H -pyrazole according to a procedure previously described by the research group of one of the authors (Arán et al 1999). 1-Methyl-1 H -pyrazole-3,5-dicarbaldehyde was obtained from diethyl 1 H -pyrazole-3,5-dicarboxylate as described by Kumar et al (2001).…”

“…1 H -Pyrazole-3,5-dicarbaldehyde (Arán et al 1999) (372 mg, 3 mmol), was dissolved in warm methanol (180 mL) and added dropwise under an argon atmosphere to a stirred solution of tris (2-aminoethyl)amine (292 mg, 2 mmol) in methanol (120 mL). After stirring overnight at room temperature, the intermediate Schiff base was reduced in situ with solid sodium borohydride (340 mg, 9 mmol) by stepwise addition.…”

“…A solution of 1-benzyl-1 H -pyrazole-3,5-dicarbaldehyde (Arán et al 1999) (428 mg, 2 mmol) in MeCN (30 mL) was added under argon, to a solution of freshly distilled 1,5-diamino-3-azapentane (204 mg, 2·0 mmol) in the same solvent (30 mL). After stirring overnight at room temperature, the intermediate Schiff base separated as a white solid that was crystallized from EtOH (405 mg, 72%, mp 161–162 °C) (lit.…”

“…1). Macrobicyclic polyamine 1 (Lamarque et al 2001), macrocyclic polyamines 2 and 3 (Arán et al 1999; Kumar et al 2001), with N-methyl- and N-benzyl-substituted pyrazole rings, and macrocyclic analogue 4 (Miranda et al 2004), with bulky octyl groups attached to the amine nitrogens on the side-chains had been previously tested by us against Trypanosoma cruzi (Sánchez-Moreno et al 2012 a ). In those assays it was found that compounds 1 – 3 were more active against the parasite and less toxic against Vero cells than the reference drug benznidazole (BZN), whereas the behaviour of 4 was similar to that of BZN or even worse.…”