How will you prepare 2-naphthol aniline dye from aniline the reaction involved in it?

2- Naphthol aniline dye can be prepared by coupling reaction. In the presence of hydrochloric acid, aniline reacts with sodium nitrite and forms benzene diazonium chloride. A bright orange 2-naphthol aniline dye is formed by additional benzene diazonium chloride reacting with 2-naphthol.

How do you make 2-naphthol?

Traditionally, 2-naphthol is produced by a two-step process that begins with the sulfonation of naphthalene in sulfuric acid: C10H8 + H2SO4 → C10H7SO3H + H2O. The sulfonic acid group is then cleaved in molten sodium hydroxide: C10H7(SO3H) + 3 NaOH → C10H7ONa + Na2SO3 + 2 H2O.

How do you make azo dye?

Preparation of Azo Dye

  1. Generally, azo dyes are prepared by diazotization of a primary aromatic amine, then followed by coupling with one or more than one electron-rich nucleophile.
  2. Another method of preparing azo dyes is by first reducing nitroaromatic derivatives in an alkaline medium.

What is the structural formula of 2-naphthol aniline dye?

The formula for 2-naphthol aniline is C16H12N2O and it is a scarlet red dye.

How do you make aniline dye?

2-Aniline naphthol dye is made from aniline….Procedure:

  1. Dissolve 5ml of aniline in a mixture of concentrated hydrochloric acid and water.
  2. Cool the solution in ice bath between 0-5oC.
  3. Add a solution of 4gm sodium nitrite in 15ml of water drop wise with continuous shaking and controlling the temperature below 5oC.

Which solvent we used for the recrystallization of the phenyl azo B naphthol dye?

Filter the solution through a buchner funnel under suction from the pump. Wash the phenyl-azo-β-naphthol with water and dry the crystals obtained by pressing between the folds of filter paper. Recrystallise the product from glacial acetic acid.

How is beta naphthol prepared?

Beta naphthol sodium salt may be prepared by adding the sodium naphthalene sodium salt to a reaction solvent containing water and an organic solvent and hydrolyzing (S130).

Which starting material is used for the preparation of benzene azo β-naphthol?

Phenyl diazonium chloride is obtained first by the diazotization of aniline with nitrous acid as explained earlier, which on coupling with β-naphthol in the presence of NaOH solution yields the desired coupled product phenyl-azo-β-naphthol.

How will you prepare azo dye starting from aniline?

Aniline reacts with sodium nitrite in the presence of hydrochloric acid forms benzene diazonium chloride. Further benzene diazonium chloride reacts with 2-naphthol forms a bright orange colour 2-naphthol aniline dye. Azo compounds are prepared by the reaction of diazonium salts with phenol under alkaline conditions.

Which type of reaction is involved in azo dye preparation method?

Preparation of the target azo dye involves the conversion of 4-aminophenol to the diazonium ion intermediate 4-hydroxybenzenediazonium ion followed by the reaction with naphthalen-2-ol. This is a typical experiment in organic synthesis.

What is aniline color?

Aniline appears as a yellowish to brownish oily liquid with a musty fishy odor.