Diethyl Oxalate → HCID 178473079, compound

To a solution of potassium bis(trimethylsilyl)amide (8.88 g, 44.5 mmol) in 400 mL of THF was added dropwise acetophenone (4.85 mL, 41.6 mmol) at 78° C. After 1 hour, diethyl oxalate (6.2 mL, 45.8 mmol) was added dropwise at the same temperature. The reaction mixture was allowed to warm up to room temperature and stirred overnight. The solvent was removed in vacuo. The resulting yellowish solid was filtered and washed with Et2O to give the title compound 2 (10.5 g, 98%) as a sodium salt of Ethyl 2-hydroxy-4-oxo-4-phenyl-2-butenoate (2). To a solution of sodium salt of 2 in EtOH (300 mL) was added 4-amidosulfonylphenylhydrazine 1b (10 g, 44.7 mmol) at room temperature. The reaction mixture was stirred for 1 hour and then 2.4 mL of AcOH was added. The reaction mixture was refluxed for 2 hours. After cooling, the solvent was removed in vacuo. The resulting solid was purified by recrystallization with MeOH to afford the titled compound (13.5 g, 89% yield) as a white solid. mp 191.5-194.6° C. 1H NMR (300 MHz, DMSO-d6): δ 7.87 (d, J=8 Hz, 2H), 7.58-7.48 (m, 4H), 7.44-7.38 (m, 3H), 7.34-7.27 (m, 2H), 7.16 (s, 1H), 4.35 (q, J=7 Hz, 2H), 1.32 (t, J=7 Hz, 3H).

1. customThe solvent was removed in vacuo
2. filtrationThe resulting yellowish solid was filtered
3. washwashed with Et2O

ORD record

ord-7b3d90771b764daa978658242e91524a

Source dataset

uspto-grants-2015_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09096532B2