1-Iodo-4-(trifluoromethoxy)benzene → 2-Methyl-2-{2-methyl-4-[5-(4-trifluoromethoxy-phenyl)-pent-4-ynyloxy]-phenoxy}-propionic acid ethyl ester

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

The synthesis was performed following a procedure of Stara, Irena G.; Stary, Ivo; Kollarovic, Adrian; Teply, Filip; Saman, David; Fiedler, Pavel, Coupling reactions of halobenzenes with alkynes. The synthesis of phenylacetylenes and symmetrical or unsymmetrical 1,2-diphenylacetylenes, Collect. Czech. Chem. Commun. (1999), 64(4), 649-672. To a degassed (argon) solution of 178 mg (0.60 mmol) 1-iodo-4-trifluoromethoxy-benzene in 2 ml piperidine was added 29 mg (0.03 mmol) Pd(PPh3)4 and 5 mg (0.03 mmol) CuI. The reaction mixture was stirred at 50° C. for 10 min, then a solution of 152 mg (0.50 mmol) 2-methyl-2-(2-methyl-4-pent-4-ynyloxy-phenoxy)-propionic acid ethyl ester (example 13A]) in 2 ml piperidine was added dropwise within 1 h. During the addition the oil bath was slowly heated to 80° C. starting after 30 min. The reaction mixture was stirred at this temperature for 3 h and then extracted with chilled aqueous 10% KHSO4/Et2O (three times). The organic phases were washed with aqueous 10% NaCl, dried (Na2SO4) and evaporated. Purification by flash-chromatography on silica gel (n-heptane/EtOAc 95:5 to 9:1) yielded 190 mg of the title compound as a light yellow viscous oil.

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