Practical and Efficient Large-Scale Preparation of 4-Methylnicotinic Acid

An efficient process for the large-scale synthesis of 4-methylnicotinic acid is developed. The synthetic route utilized 2,6-dichloro-4-methylnicotinonitrile as the starting material, which was commercially available. The key step in the sequence was the reductive dechlorination in the presence of zinc and ammonia to provide an intermediate which was hydrolyzed to the described acid. The reaction parameters optimization and improvement of purification are also presented. This approach, suitable for batch processing, is of interest basically to research laboratories and also to suppliers in the research and fine chemicals market.