Acetic Acid → HCID 10663825, compound

Participants

Reaction Steps

In a two-necked, round-bottomed flask, 2.75 g (7.48 mmol) of the compound obtained in Stage B of Example 1 are dissolved in 60 cm3 of 80 % ethanol. Under a nitrogen stream, 18 cm3 of 2.5N sodium hydroxide are added. The mixture is left to stir at ordinary temperature for 2 h. The mixture is diluted with water, acidified with acetic acid and then the product is extracted with dichloromethane. The organic phase is washed with water and then dried. The mixture is purified by passing through a column of silica gel, eluting with isopropyl ether to obtain N-phenyl-6-hydroxy-3,4-dihydro-2,5,7,8-tetramethyl-2H-1-benzopyran-2-carboxamide (yield: 86 %; melting point: 107°-109° C.) and then the reaction is carried out as in Stage C of Example 1, replacing N-phenyl-6-acetoxy-3,4-dihydro-2,5,7,8-tetramethyl-2H-1-benzopyran-2-carboxamide with N-phenyl-6-hydroxy-3,4-dihydro-2,5,7,8-tetramethyl-2H-1-benzopyran-2-carboxamide.

Provenance & Evidence