Synthesis method of 4-phenyl-2-pyrrolidone

Abstract

The invention discloses a synthesis method of 4-phenyl-2-pyrrolidone, which comprises the following steps: by using diethyl malonate and 2-nitro-1-phenethyl ketone as raw materials, carrying out condensation reaction by using a strong Lewis base to obtain an intermediate 1, and reacting the intermediate 1 in an organic solvent under the action of palladium-carbon catalytic hydrogenation to obtain an intermediate 3-(3-methoxy carboxyl -4-phenyl-2-pyrrolidone); and finally, carrying out decarboxylation reaction under the alkaline condition of an organic solvent to obtain the final 4-phenyl-2-pyrrolidone. In addition, 4-phenyl-2-pyrrolidone can also be prepared through a Fork alkylation reaction of pyrrolidone and halogenated benzene by a one-step method. The method disclosed by the invention has the characteristics of readily available raw materials, simple reaction conditions, high yield and the like.

Description

technical field

[0001] This application relates to the technical field of organic synthesis, in particular, to a synthesis method of 4-phenyl-2-pyrrolidone. Background technique

[0002] As an important pharmaceutical intermediate, 4-phenyl-2-pyrrolidone is widely used in the synthesis of 4-phenylpiracetam and other medicines. 4-Phenylpiracetam Functions and Indications: It is a GABA analog, which can activate, protect and repair brain cells, increase the ATP / ADP ratio in the brain, promote the absorption of amino acids and phospholipids, protein synthesis and glucose utilization. No sedative, anticholinergic, antihistamine effect, used for senile mental decline syndrome, senile dementia, cerebral arteriosclerosis, memory and thinking function decline caused by cerebrovascular accident, thinking disorder caused by carbon monoxide poisoning, children's mental decline Wait.

[0003] In the prior art, the preparation of 4-phenyl-2-pyrrolidone usually requires two steps of red...

Examples

Embodiment 1

[0020] Embodiment 1 is the preparation embodiment of intermediate 1

[0021] Example 1

[0022] Add 16 grams of diethyl malonate, 300 milliliters of tetrahydrofuran and 16.5 grams of 2-nitro-1-phenethyl ketone into a 2000 milliliter single-necked flask. / L butyllithium 420 ml, reacted for 4 hours, after the reaction was completed, 200 ml of water was added dropwise, concentrated to remove the solvent, extracted with ethyl acetate, dried, and concentrated to obtain 30 g of intermediate 1. The yield is 92%.

Embodiment 2

[0025] Add 5 grams of intermediate 1, 20 milliliters of methanol and 0.1 grams of 10% palladium carbon into a 100 milliliter single-necked flask. Under the condition of stirring at 20-30 degrees, feed hydrogen gas and react for 2-3 hours. After the reaction is completed, filter the palladium carbon , the solution directly proceeds to the next reaction.

Embodiment 3

[0027] Add 5 grams of intermediate 1, 20 milliliters of ethanol and 0.1 grams of 10% palladium carbon into a 100 milliliter single-necked flask. Under the condition of stirring at 20-30 degrees, pass in hydrogen gas and react for 2-3 hours. After the reaction is completed, filter the palladium carbon , the solution directly proceeds to the next reaction.

technical field

[0001] This application relates to the technical field of organic synthesis, in particular, to a synthesis method of 4-phenyl-2-pyrrolidone. Background technique

[0002] As an important pharmaceutical intermediate, 4-phenyl-2-pyrrolidone is widely used in the synthesis of 4-phenylpiracetam and other medicines. 4-Phenylpiracetam Functions and Indications: It is a GABA analog, which can activate, protect and repair brain cells, increase the ATP / ADP ratio in the brain, promote the absorption of amino acids and phospholipids, protein synthesis and glucose utilization. No sedative, anticholinergic, antihistamine effect, used for senile mental decline syndrome, senile dementia, cerebral arteriosclerosis, memory and thinking function decline caused by cerebrovascular accident, thinking disorder caused by carbon monoxide poisoning, children's mental decline Wait.

[0003] In the prior art, the preparation of 4-phenyl-2-pyrrolidone usually requires two steps of red...

Examples

Embodiment 1

[0020] Embodiment 1 is the preparation embodiment of intermediate 1

[0021] Example 1

[0022] Add 16 grams of diethyl malonate, 300 milliliters of tetrahydrofuran and 16.5 grams of 2-nitro-1-phenethyl ketone into a 2000 milliliter single-necked flask. / L butyllithium 420 ml, reacted for 4 hours, after the reaction was completed, 200 ml of water was added dropwise, concentrated to remove the solvent, extracted with ethyl acetate, dried, and concentrated to obtain 30 g of intermediate 1. The yield is 92%.

Embodiment 2

[0025] Add 5 grams of intermediate 1, 20 milliliters of methanol and 0.1 grams of 10% palladium carbon into a 100 milliliter single-necked flask. Under the condition of stirring at 20-30 degrees, feed hydrogen gas and react for 2-3 hours. After the reaction is completed, filter the palladium carbon , the solution directly proceeds to the next reaction.

Embodiment 3

[0027] Add 5 grams of intermediate 1, 20 milliliters of ethanol and 0.1 grams of 10% palladium carbon into a 100 milliliter single-necked flask. Under the condition of stirring at 20-30 degrees, pass in hydrogen gas and react for 2-3 hours. After the reaction is completed, filter the palladium carbon , the solution directly proceeds to the next reaction.

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