Toluene → HCID 57230200, compound

Participants

Reaction Steps

A mixture of 1.60 g (0.012 mol) of rhodanine, 3.06 g (0.01 mol) of ethyl 7-(3,4-dimethoxyphenyl)-5-oxo-6-heptenoate, 0.77 g (0.01 mol) of ammonium acetate and 20 ml of toluene was heated under reflux for 8 hours. After cooling, 100 ml of water were added to the reaction mixture d with ethyl acetate (3×100 ml). The ethyl acetate layer was washed three times with water and once with a saturated saline solution, dried over magnesium sulfate, filtered and the filtrate was concentrated under reduced pressure to afford a reddish brown oily substance. The oily substance was purified by silica gel column chromatography (eluent, chloroform) to obtain 0.5 g of ethyl 7-(3,4-dimethoxyphenyl)-5-(4-oxo-2-thioxo-5-thiazolidinylidene)-6-heptenoate. To 0.21 g of this compound was added 5 ml of water and 1 ml of 5% sodium hydroxide solution and the mixture was stirred at room temperature for 3 hours. This mixture was acidified with 10% hydrochloric acid, 100 ml of water was added to the acidified mixture which was extracted with ethyl acetate (3 ×120 ml). The ethyl acetate layer was washed three times with water and once with saturated saline solution, dried over magnesium sulfate, filtered and the filtrate was concentrated under reduced pressure. The residue was purified by silica gel column chromatography (eluent, chloroform : methanol ™10:1) to obtain 0.12 g of Isomer A of 7-(3,4-dimethoxyphenyl)-5-(4-oxo-2-thioxo-5-thiazolidinylidene)-6-heptenoic acid from the first eluate and 0.03 g of Isomer B from the subsequent eluate.

Provenance & Evidence