Prepare Phenyl A20-B-Naphthol from Aniline: Complete Guid

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APPARATUS REQUIRED:

1) Aniline: 3 m

2) Sodium nitrite: 2g

3) Sodium hydroxide: 2g

4) Conc HCL : 8ML

5) B- naphthol : 3g

6) Ice

THEORY:

Phenyl a20-B-hapthol is a common example of a20 dye. It is prepared by the coupling reaction. In the laboratory, it is prepared by the action of sodium nitrite & concentration  hydrochloric acid with alkaline B- naphthol at ice cold temperature.

PROCEDERE:

3 ml of aniline in a mixture of 8 ml conC. HCL was dissolved & 16 ml of water was added. The solution was cooled in ice at 0.5°C & then added to a solution of 2gm sodium nitrite in 10 ml water dropwise with continuous shaking. In another flask 3gm of B-naphthol was dissolved in a solution of 2gm sodium hydroxide in 25 ml of water & was cooled at 0.5ºc. Finally, the filtered product was washed with cold water & dried & recrystallized from ethyl alcohol.

RESULT:

Appearance: Deep shining red crystal

Yield: 7.8gm

Melting point: 131°C

CONCLUSION:

Hence, preparation of phenyl a20-B-naphthol was done in the laboratory from aniline.

PRECAUTION:

1) All the apparatus should be dried & cleaned.

2)  The temperature should be maintained at the required level.

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