1,2,4-Trichlorobenzene → HCID 70402843, compound

Participants

Reaction Steps

The Friedel-Crafts reaction is performed by premixing about 1 molar equivalent of the appropriate thiazolone of formula 3 with about 1 molar equivalent to about 10 molar equivalents, preferably about 2 to 3 molar equivalents, of a Lewis acid catalyst in a suitable solvent, for example, petroleum ethers; a chlorinated aromatic, such as 1,2,4-trichlorobenzene or o-dichlorobenzene; carbon disulfide; nitrobenzene; or a chlorinated hydrocarbon such as carbon tetrachloride, ethylene chloride, methylene chloride, chloroform or preferably tetrachloroethane. About 1 molar equivalent to about 10 molar equivalents, preferably about 1.1 molar equivalents of the appropriate acid halide of formula 4 is added, preferably dropwise, to the mixture of thiazolone, Lewis acid, and solvent and the reaction is allowed to proceed for about 1/2 hour to about 100 hours, preferably from about 1 hour to about 10 hours depending on the reactants, the solvent, and the temperature which can be from about -78° to about 150° C., preferably about 60° to about 150° C., most preferably about 100°-120° C. Preferably the solvent is removed by distillation. The resulting heterocyclo- or acetyl- thiazolone may be isolated from the reaction mixture by any suitable art-known procedure, preferably by quenching the reaction mixture with ice water and subsequently removing the product by filtration or extraction and solvent removal or by quenching the cooled reaction mixture with hydrochloric acid and subsequently collecting the solid product by filtration. Purification can be accomplished by, for example, recrystallization, preferably from ethanol.

Provenance & Evidence