(S)-3,3-Diphenyl-1-methylpyrrolidino[1,2-c]-1,3,2-oxazaborole synthesis

Yield:112022-81-8 83%

Reaction Conditions:

in n-heptane at 40;Inert atmosphere;Reflux;Large scale;Solvent;Temperature;

Steps:

4 Example 4
Under nitrogen protection, In a reactor equipped with a reflux water separation device(S)-(+)-2-(diphenylhydroxymethyl)pyrrolidine (2.53 kg, 10 moles) and methylboronic acid (779 g, 13 moles) were added to 7.1 g of n-heptane, Slowly stirring, As the water is constantly being separated, The solution gradually becomes clear, Then adjust the stirring speed to the normal state, When there is no more water, Stop stirring, Slow down to 40 deg C, After standing overnight, Diatomaceous earth temperature filtration, The filtrate was once again cooled to -10 ° C, Stirring for 1.5 hours to complete precipitation, After filtration, 40 deg C in a double cone and dried in vacuo for 8 hours to give 2.30 kg of S-MeCBS, Yield 83% The product is a white solid, GC: 98.2%, water content: 0.31%

References:

Shanghai Hanhong Technology Co., Ltd;Ma, Shizhong;Yang, Zhaopeng;Ma, Daogong;Ji, Pengfei;Liu, Bingbing CN106478703, 2017, A Location in patent:Paragraph 0015; 0016

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