Abstract

The triarylmethyl cations produced by protonation of 3,3-diphenylphthalide and the phenolphthaleins are stable in aqueous sulphuric acid solutions but undergo further reaction in dilute oleum solutions. Cryoscopy, conductivity, and spectrophotometry show that 3,3-diphenylphthalide undergoes an irreversible cyclodehydration reaction to form 10-hydroxy-10-phenylanthracen-9-one and that the phthaleins undergo a reversible sulphation reaction resulting in closure of the lactone ring and consequently loss of colour. Phenolphthalein and 10-hydroxy-10-phenylanthracen-9-one also disulphonate in 99·9% H2SO4 and in oleums.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.