3689-45-0Relevant academic research and scientific papers
NbCl5 Promoted the Efficient Synthesis of Phthalein Derivatives: Optical Characterization and Solvatochromic Effect
Moreno, Vitor Fernandes,dos Santos, Giovanny Carvalho,da Costa, Gyordanna Mayara Gaspar,Gomes, Marcelo Henrique Ayala,Silva-Filho, Luiz Carlos da
supporting information, p. 2811 - 2821 (2019/08/26)
Organic dyes derived from phthaleins have a large number of industrial applications and can be synthesized using a Lewis acid by Friedel–Crafts acylation, followed by an addition reaction to the carbonyl compound. This work aims to investigate the use of NbCl5 as a catalyst for the acylation reaction. The behavior of the phthalein derivatives in several solvents and when subjected to different pH conditions was studied. These compounds showed a color-changing effect depending on the pH and solvent, making them useful for applications as indicators. The phthaleins change their conformations depending on the condition of the medium. Photophysical studies of these compounds were carried out through their UV–Vis absorption spectra. Here, we show the umbrella-like conformation change of phthalein derivatives that depend on the solvent and the pH of the medium.
A facile synthesis of phthalein indicator dyes
Sabnis, Ram W.
experimental part, p. 6261 - 6263 (2010/01/11)
The use of methanesulfonic acid offers a novel and highly efficient method for the synthesis of phthalein indicator dyes in excellent yields on an industrial scale.
Oral care compositions with color changing indicator
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Page/Page column 25, (2008/06/13)
The invention describes color changing toothpastes and mouthwashes which contains acid-base indicator(s) for interaction with the oral cavity to provide a color change indicative of treatment time.
Synthesis and Reactivity of 2-Aroylbenzoic Acid, III. 2-(4-Hydroxy-3,5-dimethylbenzoyl)benzoic Acid
Ruminski, Jan K.
, p. 970 - 979 (2007/10/02)
Friedel-Crafts 2-carboxybenzoylation of 2,6-xylenol with phthalic anhydride resulted in the formation of a new p-acylphenol type compound: 2-(4-hydroxy-3,5-dimethylbenzoyl)benzoic acid (1) (74percent yield).Similar reactions of 2,6-xylenol with tetrabromo- and tetrachlorophthalic anhydride gave the benzoic acid derivatives 13 and 14, respectively.Another practical and efficient (93percent) method for preparation of compound 1 was semi-Stieglitz rearrangement of the known 3,3-bis(4-hydroxy-3,5-dimethylphenyl)phthalide (9).Reactions of the acid 1 have been investigated, leading to its derivatives 2 - 12.
