Hydroxyphenylacetic acid → 2,4,4'-Trihydroxydeoxybenzoin

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

Resorcinol (1,3-dihydroxybenzene) (62.000 g, 563.1 mmol, 1.0 equiv.) and 4-Hydroxyphenylacetic acid (94.237 g, 619.4 mmol, 1.1 equiv.) were added to a 3 neck 2 L round bottomed flask fitted with a paddle, a pressure equalizing addition funnel and a thermometer and a heating mantle. Toluene (350 mL) was added to the flask to give a suspension. The reaction purged with nitrogen and the addition funnel filled with Boron trifluoride etherate (198.201 ml, 1578.0 mmol, 2.8 equiv.) via canula. The reaction was stirred at 150 rpm and boron trifluoride etherate was added in portions of 3-4 mL and the reaction heated. During addition the internal temperature rose to 100° C. The reaction went through various changes in color from yellow to dark red. After complete addition of boron trifluoride etherate the addition funnel was removed and replaced with a condenser. The reaction was stirred for 1.5 h at an internal temperature of 108° C. A sample was taken and HPLC analysis indicated the reaction was complete. The reaction was cooled and stirring stopped to give a biphasic solution. A 12% aqueous solution of sodium acetate (41 g, 336 mL) was slowly added to the reaction with stirring. The reaction was stirred for 16 hours. A precipitate formed overnight and was collected in a sintered glass funnel. The solid was dried on a vacuum oven for 16 h to give the product as a white powder (119.67 g, 87.0%).

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