1-Naphthol → 1-[4-(4-(Dimethylamino)naphthylazo)phenylazo]-4-hydroxy-naphtalene

HRID 28318

Reaction equation

HRID 28318 reaction equation
[NH2:1][C:2]1[CH:7]=[CH:6][C:5]([N:8]=[N:9][C:10]2[C:19]3[C:14](=[CH:15][CH:16]=[CH:17][CH:18]=3)[C:13]([N:20]([CH3:22])[CH3:21])=[CH:12][CH:11]=2)=[CH:4][CH:3]=1.[N:23]([O-])=O.[Na+].[C:27]1([OH:37])[C:36]2[C:31](=[CH:32][CH:33]=[CH:34][CH:35]=2)[CH:30]=[CH:29][CH:28]=1>Cl.O.[OH-].[Na+].O>[CH3:21][N:20]([CH3:22])[C:13]1[C:14]2[C:19](=[CH:18][CH:17]=[CH:16][CH:15]=2)[C:10]([N:9]=[N:8][C:5]2[CH:6]=[CH:7][C:2]([N:1]=[N:23][C:30]3[C:31]4[C:36](=[CH:35][CH:34]=[CH:33][CH:32]=4)[C:27]([OH:37])=[CH:28][CH:29]=3)=[CH:3][CH:4]=2)=[CH:11][CH:12]=1

Participants

7

Reactant 3

HCID 70051-NaphtholHCID 178385861-(4-Amino-phenylazo)-4-(dimethylamino)naphtaleneHCID 23668193Sodium Nitrite

Product 1

HCID 1358127161-[4-(4-(Dimethylamino)naphthylazo)phenylazo]-4-hydroxy-naphtaleneYield 74.2%

Reagents, catalysts & solvents 3

HCID 313Hydrochloric AcidSolventHCID 962WaterSolvent3×HCID 23719242Sodium hydroxide--water (1/1/1)Solvent

Conditions

Temperature
0 °C

Procedure

2.9 g of 1-(4-amino-phenylazo)-4-(dimethylamino)naphtalene were dissolved in a mixture of 2.5 ml of HCl 37% and 5 ml of water. The obtained solution was cooled to 0° C., followed by dropwise addition of 0.69 g of sodium nitrite in 3 ml of water, while keeping the reaction temperature below 4° C. After complete addition, stirring was continued for 45 min at about 4° C. and the obtained mixture was then added to an ice-cooled solution of 1.44 g of 1-naphtol in NaOH/water (1.1 g/11 ml, while keeping the reaction temperature below 5° C. After complete addition, the reaction mixture was further stirred for 1 h at about 5° C. and then poured into 100 ml of water. The resulting brownish precipitate was filtered off, washed with water (100 ml) and methanol (50 ml). Crystallisation in methanol gave 3.3 g of the desired product.

Workup

  1. customthe reaction temperature below 4° C
  2. additionAfter complete addition
  3. customthe reaction temperature below 5° C
  4. additionAfter complete addition
  5. stirringthe reaction mixture was further stirred for 1 h at about 5° C.
  6. filtrationThe resulting brownish precipitate was filtered off
  7. washwashed with water (100 ml) and methanol (50 ml)
  8. customCrystallisation in methanol

Sources & evidence

ORD record
ord-182c6791ac8b484092c777d8ef747440
Source dataset
uspto-grants-2008_09
Patent number
US07419620B2

Linked notes

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