Background and overview[1]
4-Methoxy-2-nitroacetanilide can be used as a pharmaceutical synthesis intermediate. If 4-methoxy-2-nitroacetanilide is inhaled, move the patient to fresh air; if skin contact occurs, remove contaminated clothing, rinse the skin thoroughly with soap and water, and seek medical attention if you feel unwell. ; 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[1]
The preparation of 4-methoxy-2-nitroacetanilide is as follows:
1) Place p-methoxyaniline (24.6g, 0.2m0l) in a 500mL beaker, quickly add 30mL acetic anhydride (molar ratio 1:2), stir vigorously, and sonicate for half an hour. At this time, the material becomes viscous. Like, take a small amount of spot plate (petroleum ether: ethyl acetate = 1:1) to complete the reaction, add 100mL water, let it stand for crystallization for 2 hours, filter out the precipitated solid, wash the filter cake with water, and dry to obtain off-white solid p-methoxyacetanilide .
2) Place p-methoxyacetanilide (16.5g, 0.lm0l) in a 500ml three-necked flask, add 100mL water, cool to 0~5°C in an ice bath, stir mechanically for half an hour, add mixed acid (concentrated sulfuric acid 30mL/concentrated nitric acid 30mL, molar ratio 1:5), cool to 0~5℃, slowly add dropwise, control to finish dropping within 1 hour, stir slowly, try not to let the splashed liquid stick to the wall of the bottle, the material in the bottle is from The off-white color slowly turns into dark yellow, rise to room temperature, and stir for 1 hour. A large amount of insoluble light yellow solid appears. The reaction is complete on the sampling point plate (petroleum ether: ethyl acetate = 1:1). Add 100~150mL of water and continue stirring for half an hour. , let stand, filter, wash with water until neutral, and dry to obtain 4-methoxy-2-nitroacetanilide as a light yellow solid.
Application
4-Methoxy-2-nitroacetanilide can be used as a pharmaceutical synthesis intermediate. For example, place 4-methoxy-2-nitroacetanilide (21g, 0.1mol) in a 500mL round-bottomed flask, add NaOH aqueous solution (12gNaOH, 100mL water, molar ratio 1:3) at 60°C, stir After 1 hour, a red solid appears. The reaction on the sampling point plate (petroleum ether: ethyl acetate = 4:1) is complete. Cool carefully to allow all the solids to precipitate. Filter out the solid, wash with water, and dry to obtain o-nitro-p-methoxyaniline as a red solid.
Main reference materials
[1] CN201611104733.5 Preparation method of o-nitro-p-methoxyaniline
