Picotamide synthesis

Yield: 3.94 g

Reaction Conditions:

with iron in toluene at 20; for 2.5 h;Cooling with ice;

Steps:

4 Example 4 Synthesis of Picotamide (4)
Add 2.3g of 4-methoxyisophthalic acid, 20mL of thionyl chloride, a few drops of N, N-After dimethylformamide, heat to reflux under stirring at 80C.The upper part of the spherical condenser is connected to a gas recovery device to remove the acid gasPass into the sodium hydroxide aqueous solution.After refluxing for 6 hours, the 4-methoxyisophthalic acid reaction was complete.Rotary evaporation to remove thionyl chloride,A viscous 4-methoxyisophthaloyl chloride substrate was obtained in a single-neck bottle.2.83g (26mmol) 3-aminomethylpyridine, 1.5g(26mmol) iron powder was placed in 50mL anhydrous toluene.Dissolve the viscous substrate in 10mL of anhydrous toluene, and slowly drip it under ice bathA toluene solution of 3-aminomethylpyridine.During the dropping process, bubbles were generated in the reaction liquid, accompanied by solid precipitation.DripAfter finishing, continue to stir under ice bath for 30 minutes and then change to room temperature stirring.The reaction solution gradually changed from dark black to white milkTurbid liquid.After stirring for 2 hours, the reaction was complete.After filtering, the filtrate was washed with saturated sodium bicarbonate solution and distilled water. Sodium sulfatedry.Sodium sulfate was removed by filtration, and toluene was removed under reduced pressure to obtain 4.17 g of light yellow solid.Light yellow crude product is recrystallized in ethanol3.94g white solid (87% yield, 99% purity).

References:

Changzhou Engineering Polytechnic College;Li Xuelian;Wu Dongen;Guo Qinghui;Xue Xuming;Sun Yutao;Ke Chengzhi CN112159347, 2021, A Location in patent:Paragraph 0027; 0036-0038