4-(2,5-Dihydroxyphen-1-yl)-crotonic acid and its derivatives, and the preparation of these compounds

US4353836A · kind A · utility

Assignee

• BASF SE

Inventors

• Michael Horner · Neustadt, DE
• Axel Nissen

Key dates

• Filing date: Feb 26, 1981
• Grant date: Oct 12, 1982
• Expiry date: Feb 26, 2001

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C59/52
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

4-(2,5-Dihydroxyphen-1-yl)-crotonic acid and its derivative (I) ##STR1## where R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are each H or C.sub.1 -C.sub.8 -alkyl, R.sup.5 is H, C.sub.1 -C.sub.30 -alkyl or C.sub.2 -C.sub.30 -alkenyl, and R' is H or an organic radical which can be split off hydrogenolytically, and a process for the preparation of the compounds I, wherein a hydroquinone II ##STR2## is reacted, in the presence of from 0.1 to 2 moles of a Lewis acid per mole of II, with PA0 (a) a vinylglycolic acid derivative IIIa ##STR3## or (b) a crotonic acid derivative IIIb ##STR4## where X is halogen, hydroxyl or C.sub.1 -C.sub.4 -alkoxy or acyloxy.