Dyes Derived from 3-Methyl- Δ4-tetrahydrophthalic and 4-Methyl-Δ4-tetrahydrophthalic Acids. Part II. Effect of Introducing a Methyl Group at Different Positions (3 or 4) and also of Decreasing Unsaturation in the Phthalic Acid Portion of Phthalein Dyes

3-Methyl-Δ⁴-tetrahydrophthalic and 4-methyl- Δ⁴-tetrahydrophthalic acids in the form of their anhy­drides have been condensed with a number of aromatic hydroxy (phenols) and hydroxyamino (m-diethylamino-phenol) compounds. The phthalein and rhodamine type of compounds, thus obtained, have been studied ana­lytically and spectrophotometrically and compared with similar compounds obtained from phthalio acid. The resorcinol compounds have also been brominated and acetylated. The effect of introducing a methyl group at position 3 or 4 and also of decreasing unsaturation in the phthalie acid portion of phthaleins has been observed.