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Synthetic method of astemizole drug intermediate N-(4-fluorobenzyl)phthalimide

A technology of phthalimide and fluorobenzyl, which is applied in the field of synthesis of N-phthalimide, an intermediate of astemizole, can solve the problems of being slow and effective after 3 to 4 days , to achieve the effect of reducing reaction temperature and reaction time, reducing intermediate links and increasing reaction yield

Inactive Publication Date: 2016-04-27
CHENGDU QIESITE TECH CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

After oral administration, the absorption is very fast, and the blood concentration reaches the peak value 1 to 4 hours after administration, but the effect is slow, and it will take effect after 3 to 4 days

Method used

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  • Synthetic method of astemizole drug intermediate N-(4-fluorobenzyl)phthalimide

Examples

Experimental program
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Effect test

example 1

[0010] In a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, and a dropping funnel, add 0.21mol of stannous chloride, 230ml of nitromethane, and 0.51mol of N-aminomethylphthalimide (2) , control the stirring speed at 130rpm, increase the solution temperature to 60°C, keep reflux for 3h, add 0.71mol of fluorobenzene, raise the temperature to 70°C after the addition, react for 19h, lower the solution temperature to 10°C, add 230ml mass fraction of 10% chlorine Potassium chloride solution, 90ml mass fraction is 25% oxalic acid solution, keep stirring speed 140rpm, maintain 90min, separate out solid, suction filtration, potassium bromide solution washing, anhydrous potassium carbonate dehydration, mass fraction is 65% cyclohexane washing, in Recrystallized in 90% acetonitrile to obtain 93.64 g of white crystal N-(4-fluorobenzyl)phthalimide with a yield of 72%.

example 2

[0012] In a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, and a dropping funnel, add 0.21mol of stannous chloride, 230ml of nitromethane, and 0.51mol of N-aminomethylphthalimide (2) , control the stirring speed at 150rpm, increase the solution temperature to 62°C, keep reflux for 3h, add 0.72mol of fluorobenzene, raise the temperature to 72°C after the addition, react for 20h, lower the solution temperature to 12°C, add 230ml mass fraction of 12% chlorine Potassium chloride solution, 90ml mass fraction is 27% oxalic acid solution, keep stirring speed 150rpm, maintain 110min, precipitate solid, filter with suction, wash with sodium sulfate solution, dehydrate phosphorus pentoxide, mass fraction is 68% cyclohexane wash, in mass fraction The fraction was recrystallized in 92% acetonitrile to obtain 98.84 g of white crystal N-(4-fluorobenzyl)phthalimide, with a yield of 76%.

example 3

[0014] In a reaction vessel equipped with a stirrer, a thermometer, a reflux condenser, and a dropping funnel, add 0.21mol of stannous chloride, 230ml of nitromethane, and 0.51mol of N-aminomethylphthalimide (2) , control the stirring speed at 170rpm, increase the solution temperature to 65°C, keep reflux for 4h, add 0.73mol of fluorobenzene, raise the temperature to 75°C after the addition, react for 21h, lower the solution temperature to 15°C, add 230ml mass fraction of 15% chlorine Potassium chloride solution, 90ml mass fraction is 30% oxalic acid solution, keeps stirring speed 160rpm, maintains 120min, precipitates solid, suction filtration, potassium bromide solution washing, anhydrous potassium carbonate dehydration, mass fraction is 70% cyclohexane washing, in Recrystallized in 95% acetonitrile to obtain 106.64 g of white crystal N-(4-fluorobenzyl)phthalimide with a yield of 82%.

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Abstract

A synthetic method of astemizole drug intermediate N-(4-fluorobenzyl)phthalimide comprises the following steps: adding 0.21mol of stannous chloride, 230ml of nitromethane and 0.51mol of N-aminomethylphthalimide to a reaction container provided with a stirrer, a thermometer, a reflux condenser and a dropping funnel, controlling the stirring speed to be 130-170rpm, heating the obtained solution to 60-65DEG C, maintaining refluxing for 3-4h, adding 0.71-0.73mol of fluorobenzene, heating to 70-75DEG C after fluorobenzene addition is finished, reacting for 19-21h, cooling the solution to 10-15DEG C, adding 230ml of a potassium chloride solution and 90ml of an oxalic acid solution, maintaining the stirring speed at 140-160rpm for 90-120min, precipitating a solid, carrying out pumping filtration, washing the obtained solid with a salt solution, dehydrating through a dehydrating agent, washing the dehydrated solid with cyclohexane, and recrystallizing the washed solid in acetonitrile to obtain a white crystal N-(4-fluorobenzyl)phthalimide.

Description

technical field [0001] The invention relates to a method for synthesizing N-(4-fluorobenzyl)phthalimide, an intermediate of astemizole. Background technique [0002] Astemizole is a powerful and long-acting H1 receptor antagonist without central effects such as drowsiness and lethargy. It is mainly used for the treatment of allergic rhinitis, allergic conjunctivitis, chronic urticaria and other allergic symptoms. Since it does not easily cross the blood-brain barrier, it does not have a central sedative effect nor an anticholinergic effect. It competes with histamine released in tissues for H1 receptors on effector cells, thereby halting the allergic effects. It is absorbed very quickly after oral administration, and the blood drug concentration reaches the peak value 1 to 4 hours after administration, but the effect is slow, and it will take effect after 3 to 4 days. The protein binding rate reaches 96%. Due to its long action time, it can maintain the effect for several...

Claims

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Application Information

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IPC IPC(8): C07D209/48
CPCC07D209/48
Inventor 彭飞
Owner CHENGDU QIESITE TECH CO LTD
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