Synthesis of Papaverine Hydrochloride with Mesitylene

Basic Information

1. Papaverine

1-3,4dimethoxybenzyl)-6,7-dimethoxyisoquinoline; CAS 58-74-2; white crystalline powder; melting point is 146 ^oC~ 148 ^oC; molecular formula is C₂₀H₂₁NO₄; molecular weight is 339.

2. Papaverine Hydrochloride

CAS 61-25-6; molecular formula is C₂₀H₂₁NO₄·HCl; molecular weight is 375.5; melting point is 226 ^oC; flash point is 172.2 ^oC; odorless, soluble in chloroform, slightly soluble in water, slightly soluble in ethanol, almost insoluble in ether. This product is one of the main alkaloids in papaverine and belongs to isoquinoline derivatives. it is used in brain treatment, ischemia caused by heart and peripheral vasospasm and visceral spasm such as kidney, gallbladder or gastrointestinal tract. The synthetic reaction formula is as follows.

Synthesis of Papaverine Hydrochloride with Mesitylene

3. Mesitylene

CAS 108-67-8; molecular formula is C₉H₁₂; molecular weight is 120.192; flash point is 43 ^oC; melting point -45 ^oC; is an organic compound, colorless liquid, insoluble in water, soluble in ethanol, ether, benzene, mainly used as organic synthesis raw materials.

Synthesis Method

In a reaction kettle equipped with a stirrer, a thermometer, a dropping funnel and a nitrogen conduit, under nitrogen protection, add 2.5 kg of 3,4-dihydropapaverine hydrochloride and 7.5 kg of water, stir, and heat to dissolve and become clear Later, add 1 kg of liquid caustic soda dropwise to adjust the pH to 12~13, and then add 7.5 kg of mesitylene for extraction. 500 g Raney Ni was added to the organic phase, heated to 150 ^oC, and reacted for 4 hours. Filter to obtain 2.5 kg of papaverine wet product with a purity of 99.5%. Under nitrogen protection, the resulting papaverine was added to a mixed solution of 37% hydrochloric acid 1.5 kg, water 1.3 kg, and absolute ethanol 10.3 kg. After heating up and dissolving, 50 g of activated carbon was added for decolorization, filtered, and the filtrate was cooled and crystallized to obtain papaverine hydrochloride 2.1 kg, the total yield is 74.5%, and the purity is 99.8%.