Реакция #1689214

Уравнение реакции

2-methyl-1-naphthol

1-(5-Amino-2-hydroxyphenyl)ethane-1,2-diol

compound 1

1-(5-Amino-2-hydroxyphenyl)ethane-1,2-diol

→

4-aminophenol

2-methyl-1-naphthol

Условия реакции

Обработка

1. 1
   Другоеproduces a color which

Методика

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.

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