• Journal Article

An Improved Synthesis of (4-{4-Hydroxy-3-isopropyl-5-[(4-nitrophenyl)ethynyl]benzyl}-3,5-dimethyl phenoxy)acetic Acid (NH-3)

Citation

Gopinathan, M., & Rehder, K. (2009). An Improved Synthesis of (4-{4-Hydroxy-3-isopropyl-5-[(4-nitrophenyl)ethynyl]benzyl}-3,5-dimethyl phenoxy)acetic Acid (NH-3). Synthesis, 2009(9), 1428-1430. DOI: 10.1055/s-0028-1088041

Abstract

Sonogashira coupling of methyl {4-[3-iodo-5-isopropyl-4-(methoxymethoxy)benzyl]-3,5-dimethylphenoxy}acetate with (trimethylsilyl)acetylene afforded the corresponding (trimethylsilyl)ethynyl derivative in quantitative yield. Copper-free palladium-catalyzed coupling of this intermediate with 1-iodo-4-nitrobenzene afforded methyl (4-{3-isopropyl-4-(methoxymethoxy)-5-[(4-nitrophenyl)ethynyl]benzyl}-3,5-dimethylphenoxy)acetate in high yield. Saponification of the ester group, followed by the removal of the methoxymethyl group afforded (4-{4-hydroxy-3-isopropyl-5-[(4-nitrophenyl)ethynyl]benzyl}-3,5-dimethylphenoxy)acetic acid (NH-3).