ChemInform Abstract: N(1)‐SUBSTITUIERTE 1H‐INDAZOL‐3‐CARBONSAEUREETHYLESTER UND 1H‐INDAZOL‐3‐HYDROXAMSAEUREN

Abstract

Durch Reaktion der nach früher beschriebenen Methoden erhaltenen Indazol‐carbonsäureester (I) mit Säurechloriden (II) werden die N‐Acyl‐indazolcarbonsäureester (III) erhalten.

Design, synthesis and evaluation of N-benzoylindazole derivatives and analogues as inhibitors of human neutrophil elastase

“…Compounds 5l, 5o , and 5p were obtained from 1H-indazole-3-carboxylic acid ethyl ester 4 32 and the appropriate acid, following the same procedure described for 3l, 3o and 3p . Compounds 5l and 5o were purified by column chromatography using toluene/ethyl acetate (8:2) as eluent, while compound 5p was purified by crystallization from ethanol.…”

“…Compounds 5m, 5q and 5r were obtained from compound 4 , 32 following the general procedure described for 3a–k, 3m and 3q . For compound 5m , cold water (15 mL) was added after evaporation of the solvent, and the mixture was neutralized with 0.5 N NaOH.…”

“…Compounds 5n and 5s were obtained from 4 32 and the appropriate carboxylic acid, following the same procedure as described for 3n . Compound 5n was purified by column chromatography using CH 2 Cl 2 /MeOH 9.5:0.5 as eluent, and compound 5q was recrystallized with ethanol.…”

“…The synthesis of all compounds bearing an aroyl fragment [compounds 3a–q, 5a–s ( 5a , 32 5b–k 33 ), and 8a–p ] or an acyl fragment [compounds 6a–e ( 6a 32 )] at position 1 of the indazole nucleus is depicted in Scheme 1, and the final products are grouped into the 3, 5, 6 or 8 series in order to facilitate discussion of the pharmacological results. Using previously described conditions, we first transformed the commercially available indazole-3-carboxylic acid 1 into the corresponding phenylamide 2 34 and the known esters 4 32 and 7a–c . 35 The novel 7d was prepared from a reaction of 1 with trifluoroethanol via the acid chloride.…”

Facile Access to 1H‐Indazoles through Iodobenzene‐Catalyzed C–H Amination under Mild, Transition‐Metal‐Free Conditions

“…1 H ‐Indazole and its derivatives are known to be important structural units for the development of pharmaceutically important molecules 1. For instance, they present antiarthritic,2 anti‐inflammatory,3 and antifertility activities 4. Traditional syntheses of 1 H ‐indazoles often require harsh reaction conditions, toxic reagents, and unstable intermediates, all of which have restricted their substrate scope and their industrial application 5.…”