2-Formylfuran-5-boronic acid synthesis
- Product Name:2-Formylfuran-5-boronic acid
- CAS Number:27329-70-0
- Molecular formula:C5H5BO4
- Molecular Weight:139.9
13529-27-6
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$36.97/5G
27329-70-0
456 suppliers
$6.00/1g
Yield:27329-70-0 75%
Reaction Conditions:
Stage #1:2-(diethoxymethyl)furan with Triisopropyl borate;lithium diisopropyl amide in tetrahydrofuran;n-heptane;ethylbenzene at -10 - 0; for 1 h;
Stage #2: with hydrogenchloride in tetrahydrofuran;n-heptane;ethylbenzene;water at 30;
Steps:
Example
A dried 500 mL 3-neck flask with mechanical stirrer, internal thermometer and addition funnel under nitrogen is charged with 20,16 g (0,118 mol) furfuraldiethylacetal, 33,4 g (0,177 mol) triisopropylborate and 40 mL of anhydrous THF. The water content of the reaction mixture was measured according to the Karl-Fischer-titration method and was determined to be less than 800 µg/mL of water. The solution is cooled to an internal temperature of -10°C. Keeping the temperature at -10°C to 0°C 84 mL (25 wt%, 1.84 M solution THF, heptane, ethylbenzene from Chemmetal, content determined by titration, 1.3 equivalents) LDA was added via addition funnel to the reaction mixture over a period of 1 hour. Using a canula the reaction mixture was subsequently transferred to precooled aqueous hydrochloric acid which was obtained by mixing 33 mL of concentrated hydrochloric acid and 55 mL water. The reaction temperature was maintained at a temperature of less than 30°C. The resulting tan slurry of 5-formyl-2-furylboronic acid was cooled to 0°C and filtered. The filter cake was washed twice with 20 mL of cold water to give 17.6 g of wet cake. Drying (40°C, vacuum oven) gave 12.41 g of an off-white product. The overall yield of 5-formyl-2-furylboronic acid was 75%. The content of unreacted furfural in the crude product was determined to be less than 0,1%.
References:
Degussa AG EP1403271, 2004, A1 Location in patent:Page 3, 4
13529-27-6
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$36.97/5G
121-43-7
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27329-70-0
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$6.00/1g
1708-41-4
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27329-70-0
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1899-24-7
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5419-55-6
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$12.00/5g
27329-70-0
456 suppliers
$6.00/1g