Reaktion #595853

Reaktionsgleichung

Tri(isopropyl)borate

4-(1-adamantyl)-6-bromobenzo[1,3]dioxole

dry ice acetone

n-BuLi

→

3-(1-adamantyl)-4,5-methylenedioxyphenylboronic acid

Ausbeute 65.5%

Lösungsmittel

THF

hexane

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.STIRRINGthe resulting solution was stirred at −78° C. for 20 min more
2. 2
   Temperaturto warm to room temperature
3. 3
   workup.STIRRINGwith stirring overnight
4. 4
   SonstigeThe mixture was quenched with 1 N HCl (40 mL)
5. 5
   Extraktionextracted with EtOAc (100 and 40 mL)
6. 6
   WaschenThe combined organic extracts were washed with brine
7. 7
   Sonstigedried
8. 8
   SonstigeSolvents were removed at reduced pressure
9. 9
   Waschenthe residue was washed with hexane
10. 10
    Sonstigedried

Vorschrift

To a solution of 4-(1-adamantyl)-6-bromobenzo[1,3]dioxole (2.10 g, 6.26 mmol) in THF (11 mL) at −78° C. (dry ice/acetone bath) under argon was added 1.6 M n-BuLi (10.0 mmol) in hexane (6.26 mL) in one portion. This mixture was stirred at −78° C. for 15 min. Tri(isopropyl)borate (4.30 mL, 18.8 mmol) was added, and the resulting solution was stirred at −78° C. for 20 min more before being allowed to warm to room temperature with stirring overnight. The mixture was quenched with 1 N HCl (40 mL) and then extracted with EtOAc (100 and 40 mL). The combined organic extracts were washed with brine and dried. Solvents were removed at reduced pressure, and the residue was washed with hexane and dried to give 1.23 g (65%) of 3-(1-adamantyl)-4,5-methylenedioxyphenylboronic acid as a cream solid, mp 258-261° C. IR 3231, 2903, 2849, 1343, 1164 cm−1; 1H NMR δ (CDCl3) 1.81 (bs, 6H, AdCH2), 2.13 (bs, 9H, AdCH2 and AdCH), 6.02 (s, 2H, CH2), 7.48 (s, 1H, 6-ArH), 7.75 ppm (s, 1H, 2-ArH).

Quelle