An industrially feasible synthesis of 4-chloro-1-[trans-4-(trans-4-propylcyclohexyl)cyclohexyl]benzene

An efficient and industrially feasible synthesis of 4-chloro-1-[ trans -4-( trans -4-propylcyclohexyl)cyclohexyl]benzene is reported for the first time. The chlorinated intermediate was evaluated as an alternative precursor to the corresponding brominated analogue for the preparation of trans , trans -3,4-difluoro-4′-(4′-propylbicyclohexyl-4-yl)biphenyl, an important liquid-crystal compound. The route uses readily available starting materials and avoids highly hazardous reagents, improving process safety and operational practicality. Key reaction parameters were optimized to provide consistent product quality and satisfactory yields, and the process was demonstrated on a 10 L scale without significant scale-up effects. Suzuki coupling experiments further showed that the chlorinated intermediate could effectively replace the commercially available brominated analogue in the preparation of the target liquid-crystal compound. These results demonstrate the industrial applicability of the developed process.