METHYL 4-(4-BROMOPHENYL)-2,4-DIOXOBUTANOATE synthesis

Yield:60395-85-9 86%

Reaction Conditions:

Stage #1: para-bromoacetophenonewith sodium hydride in tetrahydrofuran;mineral oil; for 0.5 h;
Stage #2: Dimethyl oxalate in tetrahydrofuran;mineral oil at 70;

Steps:

2.1 Step 1: preparation of methyl 4-(4-bromophenyl)-2,4-dioxobutanoate (T2-b)

1-(4-bromophenyl)ethanone (T2-a) (1.0 g, 5 mmol) was dissolved in dry tetrahydrofuran (20 mL), sodium hydride (0.24 g, 6 mmol) was added, the reaction was stirred for 30 minutes, and dimethyl oxalate (0.65 g, 5.5 mmol) was added. The reaction was stirred at 70°C overnight, and cooled. The mixture was added with water and ethyl acetate, the organic phase was washed with water, dried, concentrated, and the residue was purified by column chromatography on silica gel, to afford the title compound of this step (1.2 g, yield: 86%).

References:

EP3730491,2020,A1 Location in patent:Paragraph 0124-0125