Hydrochloric Acid → HCID 22906456, compound

Participants

Reaction Steps

300 ml in dichloromethane of 9.11 g of 5,6-dimethoxy-2-(4-hydroxyphenylthio)-7-isopropoxychromone obtained in EXAMPLE 22, 4.52 g of N-t-butoxycarbonyl(Boc)glycine, and 5.32 g of dicyclohexylcarbodiimide (DCC) was stirred over 3.5 hours at room temperature. The solution thus reacted was gravitationally filtered. The solvent was distilled out from the flitrate, so that 10.95 g of N-t-butoxycarbonyl(Boc)glycine ester was obtained. 5.27 g of N-tbutoxycarbonyl(Boc)glycine ester thus prepared was dissolved in 100 ml of ethyl acetate. Then, hydrochloric acid gas was introduced and bubbled in the solution for 10 min., followed by stirring for 1 hour. Subsequently, 200 ml ether was added and the resulting crystals were collected by filtration and then dried, whereby 3.53 g of 5,6-dimethoxy-2-(4-glycyloxyphenylthio)-7-isopropoxychromone hydrochloride with the following physicochemical properties was obtained.

Provenance & Evidence