Diformyl-5-hydroxyphenyl acetamide

Submitted by Jurgen Hocker and Henning Giesecke1 Checked by G Saucy Harvey Gurien, and Gerald Kaplan 

4-Bis( l, i-diphenylimidazolidin-2-yl)-5-hydroxy-phenyl] acetamide. A 500-mL, 3-necked flask equipped with nitrogen inlet, mechanical stirrer, reflux condenser, and thermometer is charged with 88.8 g (0.2 mol) of l,l 3,3 -tetraphenyl-2,2 -biimidazolidinylidene (Note 1) and 30.2 g (0.2 mol) of 3-acetami-dophenol (Note 2). The system is flushed with and maintained under nitrogen, and 100 mL of chlorobenzene (Note 3) is added. The suspension is stirred at 100°C for 6 hr (Note 4). 2-Propanol (250 mL) is added to the hot mixture, which is then allowed to cool to room temperature. A pale yellow solid precipitates which is filtered and washed with 200 mL of 2-propanol. Drying in vacuum affords 84.6-93.2 g (71-78%) of N-[2,4-bis(l,3-diphenylimi-dazolidin-2-yl)-5-hydroxyphenyl]acetamide, mp 254-256°C (Note 5). 

4-Diformyl-5-hydroxyphenyl)acetamide. A suspension of 95 g of the phenol (prepared under Section A) (Note 6) in 1 L of aqueous 10% hydrochloric acid is stirred for 2 hr at room temperature. The colorless solid (Note 7) is filtered by suction and twice suspended in water at 40°C. Final filtration is followed with a water wash (1 L, 40°C), and the solid is sucked down on the filter. Crystallization from 800 mL of acetonitrile affords 21.8-22.3 g (66-67.5%) of N-(2,4-diformyl-5-hydroxyphenyl)acetamide, mp 215-217°C (Note 8). 

The checkers purchased 3-acetamidophenol from Aldrich Chemical Company, Inc. 

The phenol should be ground in a mortar to eliminate lumps. 

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A-(2,4-DIFORMYL-5-HYDROXYPHENYL)ACET AMIDE (Acetamide, N-(2,4-diformyl-5-hydroxyphenyl)-)... 

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