Preparation method of 2-amino-5,6-dimethylpyridine_Industrial additives

Background and overview of the preparation method of 2-amino-5,6-dimethylpyridine

Pyridine is the most common compound in the six-membered heterocyclic class. Pyridine is a colorless and slightly yellow liquid with weak alkalinity and special odor. It has a specific gravity of 0.978, a boiling point of 115.56°C, and a freezing point of -42°C. It is miscible with water, ethanol, ether, etc. Pyridine is prone to nucleophilic substitution reactions, and the substituent enters the α-position. Under strong conditions, electrophilic substitution reaction can occur, and the substituent enters the β-position. Pyridine and its derivatives are widely found in nature. Niacin and nicotinamide in B vitamins have pyridine rings in their molecular structures, and some alkaloids often contain pyridine rings. 2-Amino-5,6-dimethylpyridine is a pyridine derivative that can be used as a pharmaceutical synthesis intermediate. If 2-amino-5,6-dimethylpyridine is inhaled, move the patient to fresh air; if skin contact occurs, remove contaminated dimethylaminopyridine clothing and rinse the skin thoroughly with soap and water, if any If you feel unwell, seek medical attention with Tetrahydrofuran. If eye contact occurs, separate your eyelids, rinse with running water or saline, and seek medical attention immediately. If ingested, rinse your mouth immediately. Do not induce vomiting and seek medical attention immediately.

Preparation method of 2-amino-5,6-dimethylpyridine

2-Amino-5,6-lutidine was prepared as follows: 2-amino-5-bromo-6-methylpyridine (561mg, 3.0mmol), K2CO3 (1.24g, 9.0mmol) and Pd A mixture of (dppf)Cl2*CH2Cl2 (245 mg, 0.30 mmol) was added to the solution. A solution of trimethylboroxane (377 mg, 3.0 mmol) in water (1 mL) and dioxane (10 mL) was added. The mixture was heated to reflux for 3 hours. After cooling to room temperature, the mixture was poured into water (50 mL). The mixture was extracted with diethyl ether (3 x 50 ml) and the combined organic phases were dried (Na2SO4) and concentrated. Purification by chromatography (EtOAc/heptane) gave the title compound, 2-amino-5,6-dimethylpyridine, as a dark brown solid. Yield: 244mg (67%). 2-Amino-5,6-lutidine, yield: 244 mg (67%). 1HNMR (DMSO-d6, MHz) δ7.09 (d, 1H), 6.18 (d, 1H), 5.50 (br.s, 2H), 2.18 (s, 3H), 2.03 (s, 3H).