- Novel Convenient Synthesis of 10B-Enriched Sodium Borohydride
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A convenient and efficient synthesis of 10B-enriched sodium borohydride [Na10BH4] from commercially available 10B-enriched boric acid [10B(OH)3] is described. The reaction sequence 10B(OH)3 → 10B(On-Bu)3 → 10BH3·Et3N → Na10BH4 afforded the product in 60-80% yield. The reaction was successfully scaled to hundreds of gram per run.
- Safronov, Alexander V.,Jalisatgi, Satish S.,Hawthorne, M. Frederick
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- A new synthetic route to boron-10 enriched pentaborane(9) from boric acid and its conversion to anti-10B18H22
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Boron-10 enriched boric acid, H310BO3, was converted to the corresponding sodium borohydride, Na10BH4, in essentially quantitative yields, by using slightly modified literature methods involving the formation of butyl borate, (n-OBu)310B, first and then reacting it with NaH in mineral oil. The oxidation reaction of Na10BH4 with I2 in diglyme and subsequent addition/purification in dioxane gave Na[10B3H8]0.3(C4H8O2) that reacted further with NiCl2 in either anhydrous benzene or heavy mineral oil at 110 °C to produce the corresponding 10B5H9 as the first isolated 10B-enriched liquid boron hydride in a laboratory environment. Treatment of this 10B5H9 with NaH or t-BuLi in 2:1 molar ratio underwent a cage expansion reaction to produce the [M]10B9H14 that undergoes a redox reaction in situ with anhydrous NiCl2 in n-hexane to yield the corresponding fused cage anti-10B18H22 as the only solid borane product in 42% yield, thus establishing new synthetic routes for the preparation of 10B-enriched polyhedral boranes. Copyright
- Adams, Luqman,Hosmane, Sumathy N.,Eklund, Jamey E.,Wang, Jianhui,Hosmane, Narayan S.
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- Preparation method of 4-(borono-10B)-L-phenylalanine
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The invention discloses a preparation method of 4-(borono-10B)-L-phenylalanine. The preparation method comprises the following steps: preparing an intermediate, namely N-Boc-4-(borono-10B)-L-phenylalanine by from N-Boc-4-iodo-L-phenylalanine and tri-n-butyl 10-borate; and adding N-Boc-4-(borono-10B)-L-phenylalanine and acetone into a reactor, adding a hydrochloric acid solution, conducting uniformstirring at room temperature, performing heating for a reaction, conducting distilling to remove acetone, reducing the temperature of a residual reaction solution to 10 DEG C or below, regulating a pH value to 5.5-6.5, separating out white solids, filtering out the white solids, conducting pulping and washing with dichloromethane, filtering out the residual solids, and carrying out vacuum dryingto obtain 4-(borono-10B)-L-phenylalanine. By changing a feeding sequence and controlling a reaction rate, the requirement of the reaction on the temperature is lowered, the reaction can be smoothly carried out under a relatively mild low-temperature condition, the consumption of n-butyllithium and borate is reduced, post-reaction treatment is simpler, yield is higher, production cost is greatly saved, and industrialization of the product is made possible.
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Paragraph 0024-0026; 0028-0030; 0032-0034
(2021/03/31)
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- METHOD FOR PREPARING L-BPA
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Provided is a method for preparing L-BPA, which includes steps of: reacting N-protected (S)-4-halophenylalanine of Formula I, a boronating agent, Grignard reagent and bis(2-methylaminoethyl)ether to obtain a reaction mixture, wherein the reaction mixture comprises N-protected (S)-4-boronophenylalanine of Formula II and the R2 group represents a protecting group; isolating the N-protected (S)-4-boronophenylalanine from the reaction mixture; and deprotecting the R2 group of the N-protected (S)-4-boronophenylalanine to obtain L-BPA, wherein the L-BPA has a structure of Formula III.
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Paragraph 0097-0102
(2018/06/15)
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- SYNTHESIS OF BORANE COMPOUNDS
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The present invention is directed to a process for the synthesis of alkali metal tetrahydroborates-10B and amine borane-10B precursors, such as sodium tetrahydroborate-10B and triethylamine borane-10B.
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Paragraph 0056
(2016/12/22)
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