What are the applications, properties, and synthesis methods of 2-Picoline?

2-Picoline is a versatile compound used in industries such as pesticides, pharmaceuticals, and curtain fabrics. Originally derived from pyridine fractions in coal tar, the production of 2-Picoline was limited and impure. To meet the demand, it is now synthesized as a byproduct of pyridine production, accounting for 6-8% of the pyridine yield. However, the decline in the use of pyridine-based herbicides like paraquat has led to a significant decrease in the production of 2-Picoline. Another minor source of 2-Picoline is the production of diphenylamine, where it accounts for only 0.6% of the diphenylamine yield.

Properties

2-Picoline is a colorless oily liquid with a strong unpleasant pyridine odor. It is soluble in acetone and ether, and miscible with water and ethanol.

Applications

2-Picoline has various applications, including the production of 2-vinylpyridine, nitrogen fertilizer enhancer (N-Serve), long-lasting sulfonamides, anti-silicosis drugs, livestock dewormers, poultry medications, organic phosphorus detoxifiers, local anesthetics, laxatives, additives in photographic films, dye intermediates, and rubber accelerators.

Synthesis Method

A method for synthesizing 2-Picoline from 5-ketohexanenitrile (acetylbutyronitrile) is described. The method involves using a fixed-bed reactor filled with granular catalysts, hydrogen gas, and operating at a temperature of 380-420°C and a pressure of 0.02-0. IMPa. The loading of 5-ketohexanenitrile is 40-180g per liter of catalyst per hour, and the circulating hydrogen gas in the exhaust is 0.08-0.2 m3 per liter of catalyst per hour. The active components of the granular catalyst are Zn, Cr, Cu, Mn, and K, with specific ranges for each element.