ethyl acetate hexane twice then gave 1 06 g 20 of pure 4 o toluenesulfonyl 3 4 dihydro 2 1h quinoxalinone m p 149 u00b0 151 u00b0 c anal calcd for c 15 h 14 n 2 o 3 s c 59 58 h 4 67 n 9 27 found c 59 63 h 4 71 n 9 15 a solution consisting of 4 0 g 0 027 mole of 3 4 dihydro 2 1h quinoxalinone dissolved in 100 ml of chloroform containing 2 73 g 0 027 mole of triethylamine 3 74 ml was stirred in a 250 ml flask under a dry nitrogen atmosphere at room temperature u02dc 20 u00b0 c while 5 84 g 0 03 mole of p fluorobenzenesulfonyl chloride dissolved in 100 ml of chloroform was slowly added thereto in a dropwise manner the reaction mixture was then stirred at this point for a period of approximately 64 hours and finally poured into 300 ml of water extraction of the aqueous mixture with chloroform followed by evaporation of the solvent under reduced pressure then gave a solid residue which was subsequently dissolved in ethyl acetate and washed with 1n hydrochloric acid the washed ethyl acetate solution was thereafter concentrated in vacuo and.