The synthesis of DBA ynthesis 2.0 g NaOH, 20 mL H,O, cool down 16 mL EtoH added to 100 mL three-neck flask water bath RB2. 2.1 g PhCHO, 0.58 g Acetone mixed slowly added half to flask control the temperature 3. 15 min added the rest. etoh washed 4. 30 min later suction filtration, washed by H,O, dry, weigh Recrystalization Crude product is added to 50 mL round-bottomed flask EtOh is added(about 5 mL/g) 2. Water bath, reflux, EtoH is added slowly until totally dissolved 3. Cool down to r t, followed by icy water bath 4. Suction filtration, washed by H,O, dry, weigh1. 2.0 g NaOH， 20 mL H2O，cool down 16 mL EtOH added to 100 mL three-neck flask water bath 2. 2.1 g PhCHO， 0.58 g Acetone mixed slowly added half to flask control the temperature 3. 15 min added the rest， EtOH washed 4. 30 min later suction filtration , washed by H2O, dry, weigh 1. Crude product is added to 50 mL round-bottomed flask EtOH is added (about 5 mL/g ) 2. Water bath, reflux, EtOH is added slowly until totally dissolved 3. Cool down to r.t., followed by icy water bath 4. Suction filtration, washed by H2O, dry, weigh Synthesis Recrystalization The synthesis of DBA