Benzaldehyde → Ethyl cinnamoylacetate

Participants

Reaction Steps

A solution of 6.6 ml (0.06 moles) of titanium tetrachloride in 30 ml of carbon tetrachloride was added dropwise with rapid stirring to 300 ml of cold (-50° ) tetrahydrofuran. The mixture was allowed to warm to 0° and a solution of 5.85 g (0.045 moles) of ethyl acetoacetate in 50 ml of tetrahydrofuran was added dropwise over about 20 minutes. After the mixture was stirred an additional 30 minutes, a solution of 25.2 ml (0.180 moles) of triethylamine in 50 ml of tetrahydrofuran was added dropwise over 45 minutes. After the mixture was stirred an additional 45 minutes, a solution of 4.8 g (0.045 moles) of benzaldehyde in 50 ml of tetrahydrofuran was added dropwise over 30 minutes. The reaction mixture was allowed to warm to room temperature and then stirred for 24 hours. Water (50 ml) was added and the resultant two-phase mixture was stirred for two hours. After the layers were separated, the aqueous layer was extracted with 50 ml of ethyl acetate. The ethyl acetate extract was combined with the initially separated organic layer, dried over sodium sulfate, filtered, and concentrated in vacuo to 9.8 g of an oil. Chromatography on silica gel gave 7.4 g of the title compound as a solid, m.p. ca. 49°. Structure assignment was supported by nmr and infrared spectra and by elemental analysis.

Provenance & Evidence