1,1-BIS 2,3 DIHYDROXYBENZENE METHANES

摘要

Preparation of substituted 2,3-dihydrobenzofuran which can be defined by the general formula: …… wherein; Ra is hydrogen, halogen, or an alkyl radical, straight lined or branched containing from 1 to 4 carbon atoms, aryl, alkaryl, -OH, OR3 -N(Ra)2, (Rabeing, in its turn, an alkyl radical, straight lined or branched containing from 1 to 4 carbon atoms);… Rb is an alkyl radical, straight lined or branched containing from 1 to 6 carbon atoms, aryl or alkaryl;… Rc is hydrogen or has the same meaning as Rb;… by rearrangement of 1,1-bis(2-hydroxybenzene)alkyl and/or aryl-ethane, which can be defined by the general formula: …… wherein Ra, Rb and Rc have the above specified meanings, working in the presence of catalytic amounts of at least a mineral or an organic acidic compound, at a high temperature and withdrawing from the reaction mass the products of the rearrangement reactions they are being formed. …The 1,1-bis(2-hydroxybenzene)alkyl and/or arylethane are obtained starting from substituted phenols and aldehydes under the influence of specially provided catalysts. …Within the scope of this reaction, 1,1-bis(2,3-dihydroxybenzene)alkyl or aryl-methane are found, which can be defined by the general formula: …… wherein; R is an alkyl radical, straight lined or branched, containing from 1 to 20 carbon atoms, or an aryl radical;… R1, R2 and R3 are equal to or different from each other and represent: H, halogen, or the alkyl radical, straight lined or branched, containing from 1 to 4 carbon atoms, aryl, alkaryl, -OH, -OR4, -N(R4)2, R4 being an alkyl radical, straight lined or branched, containing from 1 to 4 carbon atoms. …Such compounds are obtained by reaction of a biphenol which can be defined by the general formula: …… with an aldehyde which can be defined by the general formula… R-CHO… wherein R, R1 R2 and R3 have the meanings specified hereinabove, working in the presence of catalytic amounts of at least one compound, which is a member selected from the group consisting of oxides, hydroxides, alcoholates and carboyxlates of the metals belonging to the IA, IIA, IIB and VIIB of the Periodic System of the Elements, in the presence, or not, of a liquid and inert (i.e. nonreactive) organic solvent, the water being formed as a reaction byproduct being optionally withdrawn as it is formed.