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Preparation of luminol

first Preparation of 3-nitroftalové

            

175 g phthalic anhydride mix together with 175 ml 65% HNO 3 and 175 ml 97% H 2 SO 4 in elrenmayerově flask ca 1 l mixture of 3 hours to heat the steam bath. Then the mixture is poured into 3 l of cold water. This gives a mixture of isomers where we want is insoluble in water.              T.T = 216-218 ° C, yield about 70 g

                         

second The actual preparation of luminol

            

                            In 20 ml beaker mix 1.0 g of 3-nitroftalové, 3 ml of glycerol, 15 ml of water, an aqueous solution of 0.62 g Hydrazine sulfate and aqueous 0.19 g NaOH (just enough water to dissolve). Heat the mixture at atmospheric pressure to about 120 ° C for 8-10 minutes (this operation is to boil the excess water, glycerin has a boiling point higher than 120 ° C and remains in solution). The mixture is cooled to 100 ° C and add 15 ml of hot water and the resulting precipitate was filtered.              Yield: about 0.70 g             

             

                   To these 0.70 g add 5 ml 10% NaOH solution and 3 g Na 2 S 2 O 4 to give a reddish solution, which cook about 5 minutes. Then add 2 ml of acetic acid and the pale yellow product (luminol) to frit sucked.              The yield of about 0.20 to 0.30 g                            

        

Scheme

Příprava luminolu - reakční schéma, chemická rovnice

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