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New synthesis process of 3,6-dihydro-2H-pyran-4-boronic acid pinacol ester

A pinacol ester and new process technology, applied in 3 fields, can solve the problems of low total yield, many by-products, long steps, etc., and achieve the effects of low cost, mild and controllable reaction conditions

Inactive Publication Date: 2019-01-04
DALIAN RES & DESIGN INST OF CHEM IND
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0016] This route has long steps, many by-products, and low overall yield. Palladium-catalyzed coupling is required, and the cost is high

Method used

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  • New synthesis process of 3,6-dihydro-2H-pyran-4-boronic acid pinacol ester
  • New synthesis process of 3,6-dihydro-2H-pyran-4-boronic acid pinacol ester
  • New synthesis process of 3,6-dihydro-2H-pyran-4-boronic acid pinacol ester

Examples

Experimental program
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Effect test

Embodiment 1

[0031] Synthesis of Tetrahydropyrylhydrazone:

[0032] In a 1000mL four-neck flask, add 500mL dichloromethane and 80g tetrahydropyrone respectively, and add 200g hydrazine hydrate (80%) dropwise under the condition of stirring at 20~30°C. salt water, let stand to separate the organic phase, and concentrate to obtain 77.5 g of tetrahydropyrylhydrazone, with a yield of 85%.

[0033] Synthesis of alkenyl iodide compounds:

[0034] Add 400mL of methanol, 100g of tetrahydropyranylhydrazone, and 250g of elemental iodine to a 1000mL four-neck flask, add 200mL of triethylamine dropwise under stirring at 40~50°C, and react for 1 hour after the dropwise addition. solvent. Add 200mL of dichloromethane and 50mL of 2N hydrochloric acid to the residue, stir evenly, let stand to separate the organic phase, and use Na 2 SO 3 Excess iodine was quenched from the solution, and the organic phase was distilled under reduced pressure to obtain 140 g of 4-iodo-3,6-dihydro-2H-pyran with a yield o...

Embodiment 2

[0038] Synthesis of Tetrahydropyrylhydrazone:

[0039] Add 500mL ether and 100g tetrahydropyrone to a 1000mL four-neck flask respectively, add 215g hydrazine hydrate (80%) dropwise under the condition of stirring at 20~30°C, and keep the reaction for 2 hours after the dropwise addition. After the reaction, add 180mL saturated saline , standing to separate the organic phase, after concentration, 92.5 g of tetrahydropyrone hydrazone was obtained, with a yield of 81%.

[0040] Synthesis of alkenyl iodide compounds:

[0041] In a 1000mL four-neck flask, add 400mL ether, 80g tetrahydropyranylhydrazone, and 180g elemental iodine, and add 150mL triethylamine dropwise under stirring at 40~50°C, and react for 1 hour after the dropwise addition. The solvent was distilled off under protection. Add 200mL of dichloromethane and 50mL of 2N hydrochloric acid to the residue, stir evenly, let stand to separate the organic phase, and use Na 2 SO 3 Excess iodine was quenched from the solutio...

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Abstract

The invention relates to a new synthesis process of 3,6-dihydro-2H-pyran-4-boronic acid pinacol ester( as shown in the formula I). The new synthesis process comprises the following steps that (1) tetrahydropyranone (as shown in the formula II) is condensed with hydrazine hydrate to generate a product, namely hydrazone (as shown in the formula III); (2) under alkaline conditions, the hydrazone (asshown in the formula III) reacts with iodine to generate a compound 4-iodo-3,6-dihydro-2H-pyran (as shown in the formula IV); (3) the compound IV and a Grignard reagent are in a Grignard exchange reaction, and then coupled with isopropoxyboronic acid pinacol ester (as shown in the formula V) to prepare a target product, namely the 3,6-dihydro-2H-pyran-4-boronic acid pinacol ester. The synthesis process disclosed by the invention is high in yield, mild in reaction conditions, and suitable for large-scale industrial production.

Description

technical field [0001] The invention relates to a new synthesis process of 3,6-dihydro-2H-pyran-4-boronic acid pinacol ester, which belongs to the technical field of organic synthesis. Background technique [0002] The structural formula of 3,6-dihydro-2H-pyran-4-boronic acid pinacol ester is as follows [0003] [0004] It is mainly used in the synthesis of anti-cancer and anti-HIV drugs. There are four main synthetic routes: [0005] Route 1 uses tetrahydropyrone as a raw material, reacts with p-toluenesulfonyl hydrazide to form an intermediate, and then reacts with butyllithium and isopropanol pinacol borate to obtain the target product [0006] [0007] This route uses highly flammable butyllithium, which has great safety hazards. At the same time, the reaction temperature requirement is very low, and the energy consumption is large, which is not conducive to industrial production. [0008] Route 2 uses tetrahydropyrone as a raw material, reacts with trifluoromet...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07F5/04
CPCC07F5/04
Inventor 王可为赵文武韩建国蔡小川唐培昆
Owner DALIAN RES & DESIGN INST OF CHEM IND