Mandelic Acid → 2,2'-Bifuran
Reaktionsgleichung
C1(Cl)C(=O)C(Cl)=C(Cl)C(=[O:4])C=1Cl.[C:13]([OH:23])(=O)[CH:14]([C:16]1[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=1)O.ClC1C(Cl)=C(Cl)C=CC=1>>[O:4]1[CH:21]=[CH:20][CH:19]=[C:18]1[C:17]1[O:23][CH:13]=[CH:14][CH:16]=1Komponenten
4
Reaktionsbedingungen
- Temperatur
- 180 °C
Versuchsvorschrift
A mixture of 4.9 parts of chloranil (2:3:5:6-tetrachlorobenzoquinone), 12 parts of mandelic acid and 25 parts of trichlorobenzene is stirred for 20 hours at 180° C. The mixture is cooled to 20° C. and the precipitated solid is filtered off, washed with trichlorobenzene and then crystallised from toluene. The solid is then dissolved in chloroform, the chloroform solution extracted with a 2% aqueous solution of sodium carbonate, and the chloroform then removed by distillation. 4:8-Dichloro-3:7-diphenyl-2:6-dioxo-2:6-dihydrobenzo[1:2-b:4:5-b1 ] bifuran is obtained. The product has a melting point of 310° C.-315° C., a λ max in chloroform of 457 n.m. and a molecular extinction coefficient of 45000. The n.m.r. and mass spectra are consistent with the stated structures.