Trimethyl borate → [3-(Methylamino)phenyl]boronic acid

温度

-78 °C

161 mL (242 mmol) of 1.5M methyllithium in diethyl ether are added dropwise to a solution precooled to −78° C. of 37.6 g (202 mmol) of (3-bromophenyl)methylamine (prepared according to Example 24f) in 300 mL of tetrahydrofuran. After stirring for 1 hour at −78° C., 261 mL (444 mmol) of a 1.7M solution of tert-butyllithium in pentane are added dropwise and the medium is again stirred at −78° C. for 1 hour. At −65° C., 103.5 mL (808 mmol) of trimethyl borate are added dropwise and the reaction medium is then stirred, while allowing the temperature to rise to room temperature over 1 hour. After addition of ice, the reaction medium is extracted with a 1/1 heptane/ethyl acetate mixture and then with 1-butanol. The organic phases are combined, washed with water, dried over magnesium sulfate, filtered and evaporated; 11 g (40%) of 3-methylaminophenylboronic acid are obtained.

1. stirringthe medium is again stirred at −78° C. for 1 hour
2. stirringthe reaction medium is then stirred
3. waitto rise to room temperature over 1 hour
4. additionAfter addition of ice
5. extractionthe reaction medium is extracted with a 1/1 heptane/ethyl acetate mixture
6. washwashed with water
7. dry with materialdried over magnesium sulfate
8. filtrationfiltered
9. customevaporated

ORDレコード

ord-b428150b7c4f48f1a717c700223a4d6d

出典データセット

uspto-grants-2013_02

DOI

10.6084/m9.figshare.5104873.v1

特許番号

US08383652B2