Isopropylboronic acid synthesis
- Product Name:Isopropylboronic acid
- CAS Number:80041-89-0
- Molecular formula:C3H9BO2
- Molecular Weight:87.91
150-46-9
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$12.00/25mL
1068-55-9
338 suppliers
$20.00/25ml
80041-89-0
238 suppliers
$13.50/1G
Yield:-
Reaction Conditions:
with hydrogenchloride in tetrahydrofuran
Steps:
1.g 2-(5-Benzyloxycarbonylamino-6-oxo-2-phenyl-1,6-dihydro-1-pyrimidinyl)-N-[2-methyl-1-(4,4,5,5-tetramethyl-1,3,2-dioxaborolidin-2-yl)propyl]acetamide
g. 2-Isopropyl-4,4,5,5-tetramethyl-1,3,2-dioxaborolidine. A dry, 5 L, three-necked flask was equipped with a mechanical stirrer, a Claisen adapter holding a low-temperature thermometer and an addition funnel, and a second Claisen adapter holding an addition funnel and a nitrogen inlet. Isopropylmagnesium chloride (1.60 L, 2.0M in tetrahydrofuran) was transferred via cannula into one addition funnel, and triethylborate (467.1 g) was placed into the other addition funnel. Tetrahydrofuran (1 L) was placed in the reaction flask and was cooled to -78° C. The triethylborate and the Grignard reagent were simultaneously added dropwise over a 2 hour period, while maintaining an internal temperature of less than -50° C. Upon completion of the addition, the mixture was stirred for an additional 2 hours at -78° C. The reaction was quenched by dropwise addition of concentrated hydrochloric acid (600 mL) over 1 hour. The temperature of the mixture rose from -78° C. to -20° C., and the dark amber solution became colorless. The mixture was stirred overnight, evaporated, and extracted with ether. The combined extracts were washed with brine and dried (MgSO4). Evaporation gave crude (dihydroxy)isopropylborane as a white semi-solid (360.2 g). This material was dissolved in ethyl acetate (1 mL) and the solution was placed in a 3 L, 3-necked flask equipped with a mechanical stirrer and a nitrogen inlet.
References:
Zeneca Limited US5736535, 1998, A
7732-18-5
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76347-13-2
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$17.00/1g
80041-89-0
238 suppliers
$13.50/1G
60-29-7
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$30.00/50g
150-46-9
202 suppliers
$12.00/25mL
1068-55-9
338 suppliers
$20.00/25ml
80041-89-0
238 suppliers
$13.50/1G
688-74-4
347 suppliers
$10.40/25mL
920-39-8
230 suppliers
$68.00/100ml
80041-89-0
238 suppliers
$13.50/1G