Preparation method of 1-formyl carbazole

Abstract

The invention discloses a preparation method of 1-formyl carbazole. The method comprises the following steps of: dissolving a compound shown as formula (I) into a first anhydrous solvent, then addingstrong base, carrying out reaction with a first anhydrous solvent of 2-(trimethylsilyl)ethoxymethyl chloride to obtain a first reaction product, then reacting the first reaction product with n-butyllithium and N, N-dimethylformamide in order, and then performing treatment with a quenching agent and / or a protecting group removing agent to obtain the 1-formyl carbazole. The preparation method has the advantages of short steps, low raw material cost and mild conditions, simple and convenient post-treatment and purification operation, the total yield of the two steps can reach 80% or above, the production cost is remarkably reduced, industrial production is facilitated, the purity of the 1-formyl carbazole prepared by the preparation method can reach 99% or above, and the 1-formyl carbazole can be widely applied to the fields of OLED photoelectric materials, medicines, dyes, pesticides and the like.

Description

technical field

[0001] The invention relates to the field of organic chemical synthesis, in particular to 1-formylcarbazole and a safe and efficient preparation method thereof. Background technique

[0002] Carbazole derivatives are a large class of intermediates with a wide range of uses. Since the inductive effect of N atoms on carbazole is smaller than its conjugation effect, it can be used as a hole transport layer in the field of optoelectronics, and it has good optoelectronic properties. Other derivatives prepared from carbazole are also widely used in fields such as OLED optoelectronic materials, medicine, dyes and pesticides.

[0003] 1-Formylcarbazole is an important intermediate in organic synthesis, and other chemical products prepared from it are widely used in the field of OLED optoelectronics, medicine and fluorescent dyes. The synthesis methods of 1-formyl carbazole at home and abroad are mainly divided into two categories: one is to use nitro compounds as r...

Examples

preparation example Construction

[0046] The invention provides a kind of preparation method of 1-formylcarbazole, it comprises the following steps at least:

[0047] (1) In the first anhydrous solvent, the compound of formula (I) is mixed with a strong base, and then reacted with 2-(trimethylsilyl) ethoxymethyl chloride under suitable reaction conditions to generate the first reaction product;

[0048]

[0049] Among them, R 1 and R 2 Each independently represents hydrogen, straight-chain or branched-chain C 1 -C 20Alkyl, aryl or nitro; X ​​represents a halogen atom; and

[0050] (2) react the first reaction product with n-butyllithium and N,N-dimethylformamide sequentially in a second anhydrous solvent, then quench, and remove the protecting group with a removing agent to obtain Second reaction product.

[0051] [step 1]

[0052] Step (1) of the present invention comprises mixing the compound of formula (I) with a strong base in the first anhydrous solvent, and then carrying out the reaction with 2...

Embodiment 1

[0079] The raw materials, solvents and catalysts used in the following examples or comparative examples of the present invention are all conventional commercially available products, unless otherwise specified.

[0080] This embodiment mentions the preparation method of 3,6-dimethyl-1-formylcarbazole, specifically, including the following steps:

[0081] (1) In a 250mL dry three-necked flask, dissolve 3,6-dimethyl-1-bromocarbazole (5.48g, 20.0mmol) in anhydrous DMF (80mL), and slowly add 60 %NaH (880mg, 22mmol), end the nitrogen flow protection, continue to stir for 0.5h, slowly add SEMCl (3.67g, 22mmol) dissolved in anhydrous DMF (50mL) dropwise, continue stirring for 1.5h after adding, add 10% carbonic acid Extract with sodium hydrogen aqueous solution and DCM, wash the organic phase with water, dry over anhydrous magnesium sulfate, filter, concentrate under reduced pressure, and separate by silica gel column chromatography (developing solvent: DCM:PE=1:1) to obtain the inte...

Embodiment 2

[0084] This embodiment is a preparation method of 3,6-di-tert-butyl-1-formylcarbazole, specifically, the method comprises the following steps:

[0085] (1) In a 250mL dry three-necked flask, dissolve 3,6-di-tert-butyl-1-bromocarbazole (7.17g, 20.0mmol) in anhydrous DMF (80mL), and slowly add in batches under the protection of nitrogen flow 60% NaH (880mg, 22mmol), end the nitrogen flow protection, continue to stir for 0.5h, slowly add SEMCl (3.67g, 22mmol) dissolved in anhydrous DMF (50mL) dropwise, continue to stir for 1.5h, add 10% Sodium bicarbonate aqueous solution and DCM extraction, the organic phase was washed with water, dried over anhydrous magnesium sulfate, filtered, concentrated under reduced pressure, and separated by silica gel column chromatography (developing solvent: DCM:PE=1:1) to obtain the intermediate N-SEM protection 3,6-di-tert-butyl-1-bromocarbazole with a yield of 90%. The obtained intermediate NMR spectrum is as follows Figure 5 Shown, the obtained...

technical field

[0001] The invention relates to the field of organic chemical synthesis, in particular to 1-formylcarbazole and a safe and efficient preparation method thereof. Background technique

[0002] Carbazole derivatives are a large class of intermediates with a wide range of uses. Since the inductive effect of N atoms on carbazole is smaller than its conjugation effect, it can be used as a hole transport layer in the field of optoelectronics, and it has good optoelectronic properties. Other derivatives prepared from carbazole are also widely used in fields such as OLED optoelectronic materials, medicine, dyes and pesticides.

[0003] 1-Formylcarbazole is an important intermediate in organic synthesis, and other chemical products prepared from it are widely used in the field of OLED optoelectronics, medicine and fluorescent dyes. The synthesis methods of 1-formyl carbazole at home and abroad are mainly divided into two categories: one is to use nitro compounds as r...

Examples

preparation example Construction

[0046] The invention provides a kind of preparation method of 1-formylcarbazole, it comprises the following steps at least:

[0047] (1) In the first anhydrous solvent, the compound of formula (I) is mixed with a strong base, and then reacted with 2-(trimethylsilyl) ethoxymethyl chloride under suitable reaction conditions to generate the first reaction product;

[0048]

[0049] Among them, R 1 and R 2 Each independently represents hydrogen, straight-chain or branched-chain C 1 -C 20Alkyl, aryl or nitro; X ​​represents a halogen atom; and

[0050] (2) react the first reaction product with n-butyllithium and N,N-dimethylformamide sequentially in a second anhydrous solvent, then quench, and remove the protecting group with a removing agent to obtain Second reaction product.

[0051] [step 1]

[0052] Step (1) of the present invention comprises mixing the compound of formula (I) with a strong base in the first anhydrous solvent, and then carrying out the reaction with 2...

Embodiment 1

[0079] The raw materials, solvents and catalysts used in the following examples or comparative examples of the present invention are all conventional commercially available products, unless otherwise specified.

[0080] This embodiment mentions the preparation method of 3,6-dimethyl-1-formylcarbazole, specifically, including the following steps:

[0081] (1) In a 250mL dry three-necked flask, dissolve 3,6-dimethyl-1-bromocarbazole (5.48g, 20.0mmol) in anhydrous DMF (80mL), and slowly add 60 %NaH (880mg, 22mmol), end the nitrogen flow protection, continue to stir for 0.5h, slowly add SEMCl (3.67g, 22mmol) dissolved in anhydrous DMF (50mL) dropwise, continue stirring for 1.5h after adding, add 10% carbonic acid Extract with sodium hydrogen aqueous solution and DCM, wash the organic phase with water, dry over anhydrous magnesium sulfate, filter, concentrate under reduced pressure, and separate by silica gel column chromatography (developing solvent: DCM:PE=1:1) to obtain the inte...

Embodiment 2

[0084] This embodiment is a preparation method of 3,6-di-tert-butyl-1-formylcarbazole, specifically, the method comprises the following steps:

[0085] (1) In a 250mL dry three-necked flask, dissolve 3,6-di-tert-butyl-1-bromocarbazole (7.17g, 20.0mmol) in anhydrous DMF (80mL), and slowly add in batches under the protection of nitrogen flow 60% NaH (880mg, 22mmol), end the nitrogen flow protection, continue to stir for 0.5h, slowly add SEMCl (3.67g, 22mmol) dissolved in anhydrous DMF (50mL) dropwise, continue to stir for 1.5h, add 10% Sodium bicarbonate aqueous solution and DCM extraction, the organic phase was washed with water, dried over anhydrous magnesium sulfate, filtered, concentrated under reduced pressure, and separated by silica gel column chromatography (developing solvent: DCM:PE=1:1) to obtain the intermediate N-SEM protection 3,6-di-tert-butyl-1-bromocarbazole with a yield of 90%. The obtained intermediate NMR spectrum is as follows Figure 5 Shown, the obtained...

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