ChemInform Abstract: Selective Catalytic Hydrogenations and Hydrogenolyses. Part 7. Stereoselective Synthesis of 1‐Acyl‐2,3‐dihydro‐2‐carbalkoxy‐1H‐indole Acetic Acid Esters.

Abstract

Selective Catalytic Hydrogenations and Hydrogenolyses. Part 7. Stereoselective Synthesis of 1-Acyl-2,3-dihydro-2-carbalkoxy-1Hindole Acetic Acid Esters.-The indole acetic acid ester (V), which is obtained by an improved synthesis from (I), is stereoselectively hydrogenated via the N-acyl intermediates (VII) furnishing the cis-indolines (VIII) in high yields. The cis-compound (VIIIa) can be isomerized to the trans-derivative (X) while (VIIIb) can be cleaved selectively to the dicarbonic acid (XII). -(REIMANN, E.; ERDLE, W.; UNGER, H.; Pharmazie 54 (1999) 6, 418-421; Inst. Pharm.,

Design, Synthesis, and Structure–Activity Relationship of New 2-Aryl-3,4-dihydro-β-carbolin-2-ium Salts as Antifungal Agents

“…When compounds 6 were reduced to the corresponding 1,2,3,4-tetrahydro derivatives, their antifungal activity remarkably decreased or disappeared (unpublished results). A similar case was also found by us in antimicrobial, acaricidal, and anticancer activities of both benzo­[ c ]­phenanthridine salts and isoquinolinium salts. − (5) N 9 -Alkylation enhances the activity ( 6b vs the corresponding 6a ) (Table ). The lower activity of 6a should be attributed to the stronger acidity of N 9 -H, which can cause 6a to coexist in ionic and nonionic forms in an aqueous solution (Figure ).…”

“…The procedure was adapted from a previous paper . Briefly, phenylhydrazine–HCl (14.5 g, 100 mmol) reacted with α-ketoglutaric acid (14.6 g, 100 mmol) in water at room temperature for 12 h to provide 2-(2-phenylhydrazono)­pentanedioic acid.…”