Preparation method of triphenylmethyl bromide_Kain Industrial Additive

Background and overview^[1]

Triphenylmethyl bromide can be used as a pharmaceutical synthesis intermediate.

Preparation^[1]

A method for recovering triarylmethyl halides such as triphenylmethyl bromide from sucrose derivatization. The method includes the following steps

(a) Triarylmethylation of sucrose in the presence of amines to form 6,r,6′-tri-O-triarylmethylsucrose and triarylmethylated sucrose by-products;

(b) Acylate 6,1′,6′-tri-O-triarylmethylsucrose in the presence of amine to form 6,1′,6′-tris-O-triarylmethylsucrose pentaester and triarylmethylated sucrose ester by-products;

(c) The product of step (b) is separated into i) βjl’jβ’-tri-O-triarylmethylsucrose pentaester, and ii) a mixture containing triarylmethylated sucrose esters;

(d) Contacting the first by-product component of the mixture comprising step (c) ii) with an aqueous hydrogen halide solution under conditions sufficient to remove the amine therefrom, thereby forming a triaryl methylated compound containing one or more Washing by-product components of sucrose impurities;

(e) Contacting the washed by-product component with a hydrogen halide to cleave the triarylmethyl from the one or more triarylmethylated sucrose impurities to form a first crude triaryl A methyl halide component, including a triarylmethyl halide and one or more used triarylmethyl compounds selected from the group consisting of triarylmethanol, triarylmethyl esters and triarylmethyl ethers;

(f) contacting the first crude triarylmethyl halide with a hydrogen halide to convert the one or more spent triarylmethyl compounds into a triarylmethyl halide to form Purified triarylmethyl halide component; and

(g) Recovery of triarylmethane halide such as triphenylmethyl bromide from the output of step (f).

Main reference materials

[1] WO2008070043 – TRITYL CHLORIDE RECOVERY