4-Chloro-3-(trifluoroacetyl)- and 4-chloro-3-(methoxalyl)coumarins as novel and efficient building blocks for the regioselective synthesis of 3,4-fused coumarins

Identification of active anti-inflammatory principles of betabeta wood (<i>Lunasia amara</i> Blanco) from Siawung Barru- South Sulawesi, Indonesia

“…Compounds with basic coumarin skeleton ring structure reduce trauma or disease-induced tissue inflammation due to their antioxidant, anti-inflammatory and immunosuppressive activities [5].…”

Domino Reactions of Chromone‐3‐carboxylic Acids with Aminoheterocycles: Synthesis of Heteroannulated Pyrido[2,3‐c]coumarins and their Optical and Biological Activity

“…Our starting point was the development of suitable conditions for the synthesis of pyrido[3,2‐ c ]coumarin 3a by reaction of chromone‐3‐carboxylic acid 1a with aminopyrazole 2a (Scheme ). The aminopyrazole 2a and related aminoheterocycles used in this study were prepared as previously reported in our work related to the synthesis of heteroannulated pyridines, spirocyclic 1,4‐dihydropyridine compounds, and 3,4‐fused coumarins . The best yield of 3a (up to 90 %) was obtained under the conditions reported in entry 5 of Table using acetic acid as solvent (14 h, 60 °C).…”

(β‐D‐Ribofuranosyl)formamidine in the Design and Synthesis of 2‐(β‐D‐Ribofuranosyl)pyrimidines, Including RF‐Containing Derivatives

“…This transformation can be rationalized by assuming the initial formation of intermediate 11Ј accompanied by intramolecular nucleophilic addition of the hydroxyl group at the triple bond (Scheme 4). We also hoped to increase the scope of this reaction to include 3-(trifluoroacetyl)chromone [25] and 4-chloro-3-(trifluoroacetyl)coumarin, [26] however, these attempts were unsuccessful. Previously, alkynyl ketones have been condensed with amidines to give pyrimidines.…”