One-pot preparation of 2-bromo-9,9-diphenylfluorene

Abstract

The one-pot method for preparing 2-bromo-9,9-diphenylfluorene belongs to the technical field of organic synthesis, and comprises the following steps: (1); (2). The reaction of the present invention can be completed in one reactor, especially the chlorination reaction, without the need to separate the intermediate product, and directly add the system reactant and catalyst to carry out the subsequent reaction in which the chlorine atom is replaced by the benzene ring. The whole operation is simple and the process is reliable. , suitable for amplification; in addition, the catalyst used in the present invention can effectively reduce side reactions, improve product yield, reaching more than 90%, and because it is a solid catalyst, it can be separated by filtration after the reaction, which simplifies the post-treatment process.

Description

technical field

[0001] The invention belongs to the technical field of organic synthesis, and in particular relates to the preparation of 2-bromo-9,9-diphenylfluorene by a one-pot method. Background technique

[0002] Fluorene and its derivatives have the characteristics of a large conjugated system in the molecule, a rigid planar biphenyl structure, a wide energy gap, a high luminous efficiency, and easy modification of the structure, making them widely used in electroluminescent materials. , solar cell materials and other fields have a wide range of applications.

[0003] Dehydration reaction of tertiary alcohols with aromatic rings, Chang, Shun Li et al. (Journal of Organic Chemistry, 75(12), 4004-4013, 2010), Kim, Bok Yeong et al. (Repub. Korean Kongkae Taeho Kongbo, 2010006072), Seok, Hwan et al. (U.S.Pat.20090200928) and Lee, Seok-Jong et al. (U.S.Pat.20040157084) proposed trifluoromethanesulfonic acid and sulfuric acid as dehydrating agents, respectively. Trifluorom...

Examples

Embodiment 1

[0025] One-pot preparation of 2-bromo-9,9-diphenylfluorene, including the following steps:

[0026] (1) ;

[0027] (2) .

[0028] The specific operation of step (1) is: a) first mix 23 mmol thionyl chloride with 10 mmol 2-bromo-9-phenyl-fluoren-9-ol; b) then take 35 mmol thionyl chloride and heat to 60°C , and then dropwise add the mixed solution of step a) within 0.5h; c) chlorination reaction ends after heating up to reflux for 3h;

[0029] The specific operation of step (2) is: cool down the system after the chlorination reaction, add 8.5mmol of copper benzenesulfonate, then raise the temperature to 40°C, add 15mmol of benzene dropwise within 0.5h, and continue to heat up to 55°C for 5h , and finally filtered to remove copper benzenesulfonate, and the filtrate was concentrated under reduced pressure to obtain 2-bromo-9,9-diphenylfluorene with a yield of 95.7%.

Embodiment 2

[0031] In the present embodiment, the addition of copper benzenesulfonate is replaced by copper p-toluenesulfonate. Others are the same as in Example 1, and the final yield is 97.5%.

Embodiment 3

[0033] One-pot method for preparing 2-bromo-9,9-diphenylfluorene, the reaction formula is the same as in Example 1.

[0034] Include the following steps:

[0035] The specific operation of step (1) is: a) first mix 35 mmol phosphorus trichloride with 10 mmol 2-bromo-9-phenyl-fluoren-9-ol; b) then take 53 mmol phosphorus trichloride and heat to 70°C , and then dropwise add the mixed solution of step a) within 1 hour; c) the chlorination reaction ends after heating up and refluxing for 5 hours;

[0036] The specific operation of step (2) is: cool down the system after the chlorination reaction, add 11 mmol of copper p-toluenesulfonate, then raise the temperature to 48°C, add 22mmol of benzene dropwise within 0.5h, and continue to heat up to 60°C for reaction After 7 hours, the copper p-toluenesulfonate was removed by filtration, and the filtrate was concentrated under reduced pressure to obtain 2-bromo-9,9-diphenylfluorene with a yield of 98.9%.

technical field

[0001] The invention belongs to the technical field of organic synthesis, and in particular relates to the preparation of 2-bromo-9,9-diphenylfluorene by a one-pot method. Background technique

[0002] Fluorene and its derivatives have the characteristics of a large conjugated system in the molecule, a rigid planar biphenyl structure, a wide energy gap, a high luminous efficiency, and easy modification of the structure, making them widely used in electroluminescent materials. , solar cell materials and other fields have a wide range of applications.

[0003] Dehydration reaction of tertiary alcohols with aromatic rings, Chang, Shun Li et al. (Journal of Organic Chemistry, 75(12), 4004-4013, 2010), Kim, Bok Yeong et al. (Repub. Korean Kongkae Taeho Kongbo, 2010006072), Seok, Hwan et al. (U.S.Pat.20090200928) and Lee, Seok-Jong et al. (U.S.Pat.20040157084) proposed trifluoromethanesulfonic acid and sulfuric acid as dehydrating agents, respectively. Trifluorom...

Examples

Embodiment 1

[0025] One-pot preparation of 2-bromo-9,9-diphenylfluorene, including the following steps:

[0026] (1) ;

[0027] (2) .

[0028] The specific operation of step (1) is: a) first mix 23 mmol thionyl chloride with 10 mmol 2-bromo-9-phenyl-fluoren-9-ol; b) then take 35 mmol thionyl chloride and heat to 60°C , and then dropwise add the mixed solution of step a) within 0.5h; c) chlorination reaction ends after heating up to reflux for 3h;

[0029] The specific operation of step (2) is: cool down the system after the chlorination reaction, add 8.5mmol of copper benzenesulfonate, then raise the temperature to 40°C, add 15mmol of benzene dropwise within 0.5h, and continue to heat up to 55°C for 5h , and finally filtered to remove copper benzenesulfonate, and the filtrate was concentrated under reduced pressure to obtain 2-bromo-9,9-diphenylfluorene with a yield of 95.7%.

Embodiment 2

[0031] In the present embodiment, the addition of copper benzenesulfonate is replaced by copper p-toluenesulfonate. Others are the same as in Example 1, and the final yield is 97.5%.

Embodiment 3

[0033] One-pot method for preparing 2-bromo-9,9-diphenylfluorene, the reaction formula is the same as in Example 1.

[0034] Include the following steps:

[0035] The specific operation of step (1) is: a) first mix 35 mmol phosphorus trichloride with 10 mmol 2-bromo-9-phenyl-fluoren-9-ol; b) then take 53 mmol phosphorus trichloride and heat to 70°C , and then dropwise add the mixed solution of step a) within 1 hour; c) the chlorination reaction ends after heating up and refluxing for 5 hours;

[0036] The specific operation of step (2) is: cool down the system after the chlorination reaction, add 11 mmol of copper p-toluenesulfonate, then raise the temperature to 48°C, add 22mmol of benzene dropwise within 0.5h, and continue to heat up to 60°C for reaction After 7 hours, the copper p-toluenesulfonate was removed by filtration, and the filtrate was concentrated under reduced pressure to obtain 2-bromo-9,9-diphenylfluorene with a yield of 98.9%.

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