( Add 52 mmol (9.64 g / 6.5 mL) of 2,4-dinitrofluorobenzene solution (in 20 mL of acetone) over a period of 5 minutes. Stir for 4 hours at room temperature. Distilled to half of its volume to get residue and neutralize with 2.0 M HCl (30 mL) and filtered, washed the yellow solid with water (10 mL X 2) followed by hexane (10 mL X 2). Transferred the solid to single neck flask and add benzene (10 mL X 2), concentrated on rota evaporator under pressure to obtain 10.75 g of yellow solid product 13 in 70% yield. to get residue and neutralize with 2.0 M HCl (30 mL) and filtered, washed the yellow solid with water (10 mL X 2) followed by hexane ( 10 mL X 2). Transferred the solid to single neck flask and add benzene (10 mL X 2), concentrated on rota evaporator under pressure to obtain 7.