38469-83-9

38487-85-3

The general steps for the synthesis of 2-amino-4-methoxybenzonitrile from 2-nitro-4-methoxybenzonitrile are as follows: 1. Synthesis of intermediate 3: 2-iodo-4-methoxybenzonitrile: 4-methoxy-2-nitrobenzonitrile (5.00 g, 22.46 mmol) was dissolved in ethanol (93 mL) under nitrogen protection and 5% Pd-C (0.500 g) was added. The reaction mixture was subjected to hydrogenation at 1 atm. After 10 hours of reaction, the mixture was filtered through diatomaceous earth and washed with ethyl acetate/methanol. The filtrates were combined and concentrated under reduced pressure, and the residue was purified by silica gel column chromatography using a gradient elution with a hexane solution of 80% to 100% ethyl acetate to give 4-methoxy-2-aminobenzonitrile (3.23 g, 99% yield). 2. 4-Methoxy-2-aminobenzonitrile (1.0 g, 6.58 mmol) was dissolved in a mixed solution of water (7 mL), acetic acid (7 mL) and concentrated hydrochloric acid. Hydrochloric acid was added at room temperature, followed by the slow addition of a solution of sodium nitrite (0.513 g, 7.43 mmol) in water (2 mL) at 0 °C and the reaction was carried out for 5 min. Potassium iodide (2.18 g, 13.2 mmol) was added to the reaction mixture and after stirring at room temperature for 10 h, the reaction mixture was treated with solid sodium bisulfite and diluted with water. The product was extracted with dichloromethane, washed sequentially with saturated sodium bicarbonate solution, brine, the organic phase was dried with anhydrous sodium sulfate, filtered and concentrated under reduced pressure. The residue was purified by silica gel column chromatography using a gradient elution of 10% to 50% ethyl acetate in hexane solution to give the target intermediate (1.0 g, 59% yield).