Yield:24849-48-7 11%

Reaction Conditions:

with acetic acidInert atmosphere;Reflux;

Steps:

9 Preparation of compound AMA-1 a

A cloudy mixture of 4-hydroxyacetophenone (5 g, 52.32 mmol) and glyoxylic acid monohydrate (7.4 g, 54.32 mmol) in AcOH at room temperature under N2 atmosphere was heated to reflux overnight. The reaction was quenched with H2O (150 mL) and extracted with EA (200 mL X 3), dried over anhydrous Na2SC>4, filtered, and concentrated in vacuo. The residue was purified by flash chromatography (EA : HEX = 3 : 1 to EA : MeOH = 97 : 3) to give the title compound AMA-1 a (1.17 g, 11 %, mixture 6.61 g) as a brown solid. NMR (400 MHz, DMSO-76) d 7.94 (d, J= 8 Hz, 2H), 7.86 (d, 7= 15.6 Hz,1H), 6.90 (d, J= 8.8 Hz, 2H), 6.63 (d, 7= 15.6 Hz, 1H).

References:

WO2021/111185,2021,A1 Location in patent:Page/Page column 53