Natural anthraquinonoid dyes (alizarin and purpurin) were used as platform chemicals to synthesise sustainable alternatives to existing synthetic dyes by alkylation of hydroxy groups in the 1-and 2-positions. In comparison with the parent compounds, the derivatised dyes were insensitive to pH change, insoluble in alkali and the λmax for the mono-alkylated derivatives was unchanged and that of the bis-alkylated derivatives was reduced by 53– ...
