反应详情

In analogy to the procedure described in example 91 c], 7-[2-(5-methyl-2-phenyl-oxazol-4-yl)-ethoxy]-benzo[b]thiophene-4-carbaldehyde (example 98 a]) was treated with (ethoxy-ethoxycarbonyl-methyl)-triphenyl-phosphonium chloride [Tetrahedron 50(25), 7543-56(1994)]in 2-propanol in the presence of potassium carbonate to yield the 2Z-ethoxy-3-{7-[2-(5-methyl-2-phenyl-oxazol-4-yl)-ethoxy]-benzo[b]thiophen-4-yl}-acrylic acid ethyl ester. The 2Z-ethoxy-3-{7-[2-(5-methyl-2-phenyl-oxazol-4-yl)-ethoxy]-benzo[b]thiophen-4-yl}-acrylic acid ethyl ester was further saponified in analogy to the procedure described in example 99 to yield the 2Z-ethoxy-3-{7-[2-(5-methyl-2-phenyl-oxazol-4-yl)-ethoxy]-benzo[b]thiophen-4-yl}-acrylic acid as colorless solid.