3,5-Dichloro-4-methylbenzoic acid

To a 1000 ml four-neck reaction flask (with mechanical agitation, thermometer, dropping funnel and reflux condenser), 136 g of p-methylbenzoic acid, Followed by the addition of 272 g of dichloroacetic acid as a solvent, Then add 0.2 g of sodium tungstate dihydrate, Then add 365 grams of 30percent hydrochloric acid, stir, Heated to 50 to 60 ° C, 136 g of 30percent hydrogen peroxide was added dropwise, the dropping time was 6 hours, and the temperature was maintained at 50 to 60 ° C during the dropping. After completion of the dropwise addition, the reaction was continued for 4 hours, and the mixture was subjected to liquid chromatography (HPLC) analysis, and the raw material content (9.5percent) After the reaction is completed, the reaction solution is distilled under reduced pressure. When there is no fraction, the temperature is lowered to 20 to 30 ° C, 250 g of methanol is added, heated to reflux and then cooled again to 10 ° C The residue was filtered, filtered and the cake was washed with methanol. The cake was dried to give the product: 165.2 g, yield: 80.6percent, HPLC content: 98.5percent.Add 30g to the glass reactor equipped with thermometer, stirring paddle and condenserAfter p-methylbenzoic acid and 120 ml of water, the temperature was raised to 60 C, and chlorine gas was introduced.The reaction was monitored using a chromatogram, and when the yield was greater than 90%, the reaction was stopped.The reaction was carried out for 53 h, and the reaction solution was added to a Buchner funnel to filter.After filtration, wash with 700 ml of water.The obtained filter cake was vacuum dried at 80 C to a constant weight.Quantitative analysis by liquid chromatography, Obtaining 3, 5-dichloro-4-methylbenzoic acid with a purity of 90%, Another 8% is 3-chloro-4-methylbenzoic acid.2% is p-toluic acid.In the reactor, compound XV (510 g, 2.50 mil), carbon tetrachloride (2.5 L) were added and the catalytic amountOxybenzoyl followed by NBS (480 g, 2.70 mil).Reflux to the end of the reaction, cooling to room temperature after adding saturated sodium bicarbonate, stirring after DCM extraction, combined organic phase and then the desired compound XIII (750g, crude), directly into the next step.To a solution of

Molecular Weight:205.03
XLogP3:3.1
Hydrogen Bond Donor Count:1
Hydrogen Bond Acceptor Count:2
Rotatable Bond Count:1
Exact Mass:203.9744848
Monoisotopic Mass:203.9744848
Topological Polar Surface Area:37.3
Heavy Atom Count:12
Complexity:172
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes