Hydrochloric Acid → [3-(Methylamino)phenyl]boronic acid

HRID 250853

Reaktionsgleichung

Reaktionsgleichung von HRID 250853
C[Li].Br[C:4]1[CH:5]=[C:6]([CH:9]=[CH:10][CH:11]=1)[NH:7][CH3:8].C([Li])(C)(C)C.[B:17](OC)([O:20]C)[O:18]C.Cl>C(OCC)C.O1CCCC1>[CH3:8][NH:7][C:6]1[CH:5]=[C:4]([B:17]([OH:20])[OH:18])[CH:11]=[CH:10][CH:9]=1

Komponenten

8

Edukt 5

HCID 313Hydrochloric AcidHCID 8470Trimethyl borateHCID 70182993-Bromo-N-methylanilineHCID 178418306HCID 178418306, VerbindungHCID 178418348HCID 178418348, Verbindung

Produkt 1

HCID 23558980[3-(Methylamino)phenyl]boronic acidAusbeute 14 %

Reagenzien, Katalysatoren, Lösungsmittel 2

HCID 3283Diethyl EtherLösungsmittel2×HCID 8028TetrahydrofuranLösungsmittel

Reaktionsbedingungen

Temperatur
-70 °C

Versuchsvorschrift

166 mL (0.242 mol, 1.2 eq) of 1.6 M methyllithium in diethyl ether are added to a solution cooled to −70° C. of 37.6 g (0.202 mol, 1 eq) of 3-bromo-N-methylaniline (prepared in Example 7c) in 300 ml of tetrahydrofuran. The reaction medium is stirred at −70° C. for one hour and 306 mL (0.444 mol, 2.2 eq) of 1.5 M tert-butyllithium in diethyl ether are then added. The reaction medium is stirred at −70° C. for 45 minutes and 103.5 mL (0.808 mol, 4 eq) of trimethyl borate are then added. The reaction medium is stirred at room temperature for one hour and then hydrolyzed by addition of ice, acidified with 1 L of 2N hydrochloric acid and extracted with ethyl acetate. The organic phases are combined, washed with water and dried over magnesium sulfate. The solvent is evaporated off and 4.2 g (14%) of 3-(methylamino)phenylboronic acid are obtained. The aqueous phase is basified and extracted with ethyl acetate. The organic phases are combined, washed with water and dried over magnesium sulfate. The solvent is evaporated off and the residue is chromatographed on silica gel (8/2 heptane/ethyl acetate). 3.4 g (11%) of 3-(methylamino)phenylboronic acid are obtained.

Aufarbeitung

  1. stirringThe reaction medium is stirred at −70° C. for 45 minutes
  2. stirringThe reaction medium is stirred at room temperature for one hour
  3. additionhydrolyzed by addition of ice
  4. extractionextracted with ethyl acetate
  5. washwashed with water
  6. dry with materialdried over magnesium sulfate
  7. customThe solvent is evaporated off

Quellen und Nachweise

ORD-Eintrag
ord-20e8989d805a49b59bfede49341709c5
Quelldatensatz
uspto-grants-2011_01
Patentnummer
US07863332B2

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