• 10.1021/jo015527o
  • The Journal of Organic Chemistry
  • Volume 66
  • August 2001
  • pp 5359-5365

Equivalency of reagents key for successful synthesis


Review: Synthesized the same compound of Dioxane-Monochloroborane by the reaction of Sodium Borohydride with Dioxane-borontrichloride (experimental section, Page 5364). I found the equivalency of the reagents is very important for this reaction. The reaction between 10% excess (in moles) of Sodium Borohydride and Dioxane-borontrichloride as reported yielded mainly Dioxan-dichloroborane (doublet in 11B- NMR) instead of Dioxane-Monochloroborane (triplet in 11B-NMR). The reaction of two equivalent amount of Sodium Borohydride with Dioxane-borontrichloride gave 73% of Dioxane-Monochloroborane mixed with 27% of Dioxane-dichloroborane. Finally, three equivalent amount of Sodium Borohydride reacted with Dioxane-borontrichloride to give Dioxane-Monochloroborane with 97% purity in 24 hours. Triglyme was used at the same ratiio (3% volume) as reported. So It is evident that, using excess (3 eqv.) of Sodium Borohydride helps to proceed the reaction with single compound and also reduces the reaction time.   

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