Propanedioic acid, 2-(2,4,5-trifluorobenzoyl)-, 1,3-diethyl ester synthesis

Yield:104600-15-9 83 g

Reaction Conditions:

with triethylamine;magnesium(II) chloride in toluene at 20; for 1 h;

Steps:

Preparation of compound 3

In a 1000ml reaction flask, add 500ml of toluene as a solvent, its volume dosage is 7-8 times the weight of compound 2, 122ml of triethylamine as an acid binding agent, 64ml of diethyl malonate, and 24g of catalyst magnesium chloride is added after stirring. Stir at room temperature for 1 hour, cool down to 0°C in an ice-salt bath, dropwise add 70 g of compound 2 prepared above, compound 2: diethyl malonate: acid binding agent: catalyst=1:1.1-1.2:2.0-2.5:0.5- 1.0 The temperature is controlled at 0-5°C during the dropwise addition. After the dropwise addition, the ice-salt bath was withdrawn, and the mixture was stirred naturally for 1 hour. Slowly add 200 ml of hydrochloric acid to quench the reaction. The volume of hydrochloric acid is 2.5-3.0 times the weight of compound 2. The reaction solution is poured into a separatory funnel, the toluene layer is separated, washed with water and extracted with toluene three times. The toluene layers were combined, washed with water and saturated brine, and dried over night. The next day, the desiccant was filtered off, and toluene was recovered by vacuum distillation to obtain 83 g of an oily substance, namely the crude product of compound 3.

References:

CN113929579,2022,A Location in patent:Paragraph 0006; 0019; 0024-0025