2-Methyl-1-naphthol → 4-Aminophenol

HRID 1602032Notes

Reaction equation

HRID 1602032 reaction equation
[NH2:1][C:2]1[CH:3]=[CH:4][C:5]([OH:12])=[C:6](C(O)CO)[CH:7]=1.[CH3:13][C:14]1[CH:23]=[CH:22][C:21]2[C:16](=[CH:17][CH:18]=[CH:19][CH:20]=2)[C:15]=1[OH:24]>>[NH2:1][C:2]1[CH:3]=[CH:4][C:5]([OH:12])=[CH:6][CH:7]=1.[CH3:13][C:14]1[CH:23]=[CH:22][C:21]2[C:16](=[CH:17][CH:18]=[CH:19][CH:20]=2)[C:15]=1[OH:24]

Participants

4

Reactant 2

HCID 240552-Methyl-1-naphtholHCID 97939501-(5-Amino-2-hydroxyphenyl)ethane-1,2-diol2×

Product 2

HCID 4034-AminophenolHCID 240552-Methyl-1-naphthol

Procedure

1-(5-Amino-2-hydroxyphenyl)ethane-1,2-diol (compound 1, DiOHPAP) when coupled with 2-methyl-1-naphthol coupler produces a color which closely matches that obtained from the couple of 4-aminophenol with 2-methyl-1-naphthol. The color on piedmont hair is red, without violet tone, similar to the color derived from p-aminophenol (PAP) with 2-methyl-1-naphthol. The visual observation is also confirmed by CIBL*a*b* values (Table 3) obtained from coupling of 4-aminophenol, 1-(5-amino-2-hydroxyphenyl)ethane-1,2-diol, 2-methyl-4-aminophenol (2-MePAP) and 3-methyl-4-aminophenol (3-MePAP) with 2-methyl-1-naphthol. CIE b* value (which indicates direction of yellow and blue) decreases in order of 4-aminophenol, 1-(5-amino-2-hydroxyphenyl)ethane-1,2-diol, 2-methyl-4-aminophenol and 3-methyl-4-aminophenol. The b* value differences between PAP and compound 1,2-methyl-4-aminophenol and 3-methyl-4-aminophenol, are 3.12, 6.26 and 10.92, respectively. Compound 1 shows the smallest differences among the various PAP derivatives tested. On the other hand, CIE a* values (which indicate red and green directions) undergo little change as compared to the large change in b* value. Hue angle difference (Δh) between PAP and compound 1 is 4.37. 2-MePAP and 3-MePAP show much larger hue angle difference, 11 and 18 respectively. This finding indicates that 1-(5-amino-2-hydroxyphenyl)ethane 1,2-diol 1 is a better alternative to 4-aminophenol than 2- or 3-methyl-4-aminophenol.

Workup

  1. customproduces a color which

Sources & evidence

ORD record
ord-5accad8e98eb4d7ea6f207a2afc9f15b
Source dataset
uspto-grants-1999_11
Patent number
US05980584

Reaction notes

Loading…