A kind of preparation method of heterocyclic boronic acid compound
A technology for boronic acid compounds and heterocyclic compounds, which is applied in the field of preparation of heterocyclic boronic acid compounds, can solve problems such as time-consuming, difficult preparation of dibenzofuran-2-boronic acid, and danger of organolithium reagents, so as to increase the reaction temperature and avoid The use of explosive raw materials, the effect of reducing energy consumption and danger
Examples
Embodiment 1
[0033] Prepare dibenzofuran-2-boronic acid by the following method, the preparation method comprising the following steps:
[0034] In step (1), dibenzofuran-2-bromo and triisobutylaluminum are dissolved in tetrahydrofuran at a molar ratio of 1:3 to prepare a solution 1 with a total concentration of 5 mg / mL. Solution 1 is heated at -35°C temperature storage for later use;
[0035] In step (2), tributyl borate is dissolved in ethyl acetate to prepare a solution 2 with a concentration of 10 mg / mL;
[0036] In step (3), both solution 1 and solution 2 are continuously injected into the inflow end of a flow chemical reaction tube with a diameter of 1 mm at a flow rate of 10 mL / min for reaction. The reaction time in the reaction tube is 3 min, and the reaction temperature is 24 ° C. ;
[0037] Step (4), in the outflow end of the flow chemical reaction tube, the reaction solution flowing out is mixed with the sulfuric acid solution with a pH of 1 at a flow ratio of 1:2, and the mix...
Embodiment 2
[0039] Prepare N-methylcarbazole-2-boronic acid by following method, described preparation method comprises the steps:
[0040] In step (1), N-methylcarbazole-2-bromo and triisobutylaluminum are dissolved in tetrahydrofuran with a molar ratio of 1:2, and a solution 1 with a total concentration of 10mg / mL is prepared, and solution 1 is prepared with- Store at a temperature of 25°C for later use;
[0041] In step (2), tributyl borate is dissolved in ethyl acetate to prepare a solution 2 with a concentration of 20 mg / mL;
[0042] In step (3), both solution 1 and solution 2 are continuously injected into the inflow end of a flow chemical reaction tube with a diameter of 4mm at a flow rate of 1mL / min for reaction. The reaction time in the reaction tube is 20min, and the reaction temperature is 0°C ;
[0043]Step (4), in the outflow end of the flow chemical reaction tube, the reaction solution flowing out is mixed with a hydrochloric acid solution with a pH of 1 at a flow ratio of...
Embodiment 3
[0045] The only difference from Example 1 is that the total concentration of solution 1 in step (1) is 2 mg / mL, and the concentration of solution 2 in step (2) is 5 mg / mL.
[0046] In Example 3, the dibenzofuran-2-boronic acid product was obtained with a yield of 94.6% and a purity of 97.8%.
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Abstract
Description
Claims
Application Information
- IPC
- C07F5/02
- CPC
- C07F5/025
- Inventors
- 谢应波; 张庆