Sodium hydride → 4-(2,3-Dihydroxypropyl)-2-ethyl-2H-1,4-benzoxazin-3(4H)-one

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Reaction Steps

This same compound is prepared in a yield of 55 % by the action of ethyl-2-bromobutyrate on 2-(2,3-dihydroxypropylamino) -phenol (Method D): 4.8 g of a suspension of sodium hydride in oil are slowly added to a solution of 18 g of 2-(2,3-dihydroxypropylamino)-phenol in dimethylformamide, followed by the addition 30 minutes afterwards of 20 g of ethyl-2-bromobutyrate. The mixture is then heated for 2 hours to 60°C and then kept for a few hours at the reflux temperature of the solvent. The solvent is then eliminated under reduced pressure, the residue dissolved in chloroform and the organic phase washed with a normal aqueous solution of soda and then with water. After drying over magnesium sulphate, the chloroform is eliminated under reduced pressure and the crude product obtained is purified by recrystallisation from cyclohexane.

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