Synthesis of 1-((4-methoxyphenyl)-3-alkynes)-1H-pyrrole-2,5-diones and functionalization to triazoles

A series of alkynyl maleimides were prepared via one-step cross-coupling reaction using bromomaleimide and acetylenes under the Sonogashira conditions, affording 1-((4-methoxyphenyl)-3-alkynes)-1H-pyrrole-2,5-diones in good to high yields. These products were subsequently converted in the corresponding 1,2,3-triazole using conventional click chemistry approach. The alkynyl maleimide compound (8g) crystallized in the triclinic space group P1 with unit cell parameters a = 5.3692(6), b = 9.2513(10), c = 10.3070(11) Å, α = 85.349(4), β = 86.892(4), γ = 86.892(4)°, V = 507.31(10) Å3, and Z = 1. In the crystal the molecules are stacked parallel to the c axis and held together through a C-H⋯π and a C-H⋯O interaction.