Practical and Scalable Manufacturing Process for a Novel Dual-Acting Serotonergic Antidepressant Vilazodone

Vilazodone combines the effects of a selective serotonin reuptake inhibitor with the 5-HT1A receptor partial agonist activity. Here, we report the development of a viable and scalable process for manufacturing vilazodone that features a convergent synthetic approach, with low cost and high purity. The key indole synthesis was improved to first make up the hydrazone intermediate and then modify a pendant hydroxy group to realize a much increased overall yield. This process was successfully used to prepare >2 kg of vilazodone hydrochloride with a total yield of 56.2% and purity of 99.93%.