Hydrogen Bromide → Benzoic Acid

Beteiligte Stoffe

Reaktionsschritte

13.6 g of 4-(2-<5-chloro-2-methoxy-benzamido>-ethyl)-2-hydroxy-benzoic acid ethyl ester, M.p. 88°-89° C., (prepared by treatment of 4-(2-aminoethyl)-2-methoxy-benzoic acid. HCl with hydrobromic acid/glacial acetic acid, reaction of the resulting 4-(2-<5-chloro-2-methoxy-benzamido>-ethyl)-2-hydroxy-benzoic acid with ethanol/HCl) were dissolved in 75 ml of DMF and combined with 1.2 g of sodium hydride/80% strength in white oil. The whole was stirred for half an hour, 4.4 g of allyl bromide were added and stirring was continued for 4 hours at 65° C. The dimethylformamide was then eliminated by distillation under reduced pressure, the residue was dissolved in ether, washed with sodium hydroxide solution and water, the ether solution was concentrated by evaporation and the residue was hydrolyzed by heating with 100 ml of 10% sodium hydroxide solution in the presence of a small amount of ethanol. After cooling, the solution was acidified, the substance that had precipitated was re-precipitated from ammonia with the aid of charcoal and then crystallized from dilute methanol. The 2-allyloxy-4-(2-<5-chloro-2-methoxy-benzamido>-ethyl)-benzoic acid so obtained was found to melt at 122°-123° C.

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