Diethyl (methoxy(methoxycarbonyl)methyl)phosphonate → (Z)-2-Methoxy-3-{4-[2-(5-methyl-2-phenyl-oxazol-4-yl)-ethoxy]-benzo[b]thiophen-7-yl}-acrylic Acid Methyl Ester

Participants

Reaction Conditions

Reaction Steps

A suspension of 6.07 g (20.2 mmol) of (diethoxyphosphoryl)-methoxy acetic acid methyl ester (H. Gross, Justus Liebigs Ann. Chem. 1967, 707, 35-43), 0.86 g of lithium methylat (21.6 mmol) and 5.00 g of 4-[2-(5-methyl-2-phenyl-oxazol-4-yl)-ethoxy]-benzo[b]thiophen-7-carbaldehyde (13.5 mmol) in 50 ml of DMF was heated for 21 h at 75° C. The suspension was cooled to 0° C., the solid filtered off and washed with 30 ml of cold (−15° C.) ethanol. The filter cake was dissolved in a mixture of 100 ml dichloromethane and 60 ml of water, the organic layer separated, dried over sodium sulfate and evaporated to dryness. Thereby, 3.45 g (55%) of the title compound with a purity of 91% (GC area) were obtained as white crystals.

Provenance & Evidence