Background and overview of the preparation method of 2-iodo-3-methylpyridine
Iopyridine is an important and valuable intermediate in the synthesis of natural products and pharmaceutically important compounds. Iodinated pyridines are commonly used as precursors to generate reactive organometallic compounds such as organomagnesium and organolithium reagents. Alternatively, iodopyridine and iodoquinoline participate in carbon-carbon, carbon-oxygen and carbon-nitrogen bond formation through cross-coupling reactions, such as the reactions of Suzuki-Miyaira, Negishi, and Buchwald-Hartwig4. Iodopyridine has also been substituted with (trifluoromethyl)copper reagent to give trifluoromethyl-substituted heterocycles. 2-Iodo-3-methylpyridine is a heterocyclic organic compound that can be used as a pharmaceutical synthesis intermediate. If 2-iodo-3-methylpyridine is inhaled, calcium carbonate should move the patient to fresh air; if the skin comes into contact with calcium bicarbonate, contaminated clothing should be removed and the skin should be washed thoroughly with soap and water. If there is any discomfort , seek medical attention; if eye contact occurs, separate eyelids, rinse with running water or saline, and seek medical attention immediately; if ingested, rinse mouth immediately, do not induce vomiting, and seek medical attention immediately.
Preparation method and structure of 2-iodo-3-methylpyridine
Preparation method of 2-iodo-3-methylpyridine Preparation method
2-Iodo-3-methylpyridine is prepared as follows: 2-bromo-3-methylpyridine (0.34mL, 3.0mmol) (3.0mmol) is added to stirred nBu4ZnLi2·TMEDA (1.0 mmol) was suspended in toluene (3 mL). After 0.5 μl at room temperature, the reaction was quenched with a solution of I2 (1.27 g, 5.0 mmol) in anhydrous THF (5 mL) used as the electrophile. Stir the mixture for 1 hour (for I2) or 18 hours (for other electrophiles), then add aqueous ammonia solution (5 mL), saturated Na2S2O3Aqueous solution (5 mL) (if the electrophile is I2) and extracted with EtOAc (3 × 15 mL). The combined organic layers were dried with MgSO4, filtered and concentrated under reduced pressure, and then purified by silica chromatography to obtain oil 2-iodo-3-methylpyridine; yield: 0.58 g (88 %);
1HNMR (CDCl3, 200MHz): d=8.15 (d, J=2.0Hz, 1H), 7.43 (d, J=7.3Hz, 1H), 7.15 (dd, J=7.1, 4.7Hz, 1H), 2.38ppm (s, 3H); 13CNMR (CDCl3, 50MHz): d=147.7, 139.1, 136.7, 125.4, 122.8, 26.2ppm
