(S)-3,3-Diphenyl-1-methylpyrrolidino[1,2-c]-1,3,2-oxazaborole synthesis
- Product Name:(S)-3,3-Diphenyl-1-methylpyrrolidino[1,2-c]-1,3,2-oxazaborole
- CAS Number:112022-81-8
- Molecular formula:C18H20BNO
- Molecular Weight:277.17
13061-96-6
22348-32-9
112022-81-8
Under nitrogen protection, (R)-(+)-α,α-diphenylprolinol (2.53 kg, 10 mol) and methylboronic acid (779 g, 13 mol) as well as 7.1 L of n-heptane were added to a reactor fitted with a reflux manifold. The mixture was stirred slowly and the solution gradually clarified as the water continued to separate. The stirring speed was then adjusted to conventional. When the water was completely separated, stirring was stopped and the reaction mixture was cooled to 40 °C and left to stand overnight. The reaction mixture was filtered through diatomaceous earth, and the filtrate was further cooled to -10°C and stirred for 1.5 hours to promote precipitation. The precipitate was collected by filtration and the product was vacuum dried in a double cone vacuum dryer at 40 °C for 8 h to give 2.30 kg (S)-2-methyl-CBS-oxazaborolidine in 83% yield. The product was a white solid with a GC purity of 98.2% and a water content of 0.31%.
13061-96-6
299 suppliers
$6.00/1g
22348-32-9
420 suppliers
$10.00/1g
112022-81-8
246 suppliers
$15.00/1g
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