Reaction #1833233

Reaction equation

NH4Cl

n-BuLi

5-Bromobenzo[d][1,3]oxathiole

4,4,5,5-Tetramethyl-1,3,2-dioxaborolane

→

title compound

2-(Benzo[d][1,3]oxathiol-5-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane

Solvents

tetrahydrofuran

Conditions

Workup

1. 1
   workup.STIRRINGstirring
2. 2
   workup.WAITwas continued for 1.5 h during which
3. 3
   Otherrose to −30° C
4. 4
   Extractionextracted with ethyl acetate (2×25 mL)
5. 5
   WashThe combined extracts were washed with saturated NaCl (10 mL)
6. 6
   Dryingdried (Na2SO4)
7. 7
   Otherevaporated

Procedure

5-Bromobenzo[d][1,3]oxathiole (1.0 g, 4.6 mmol, prepared as described in Cabiddu, Salvatore; Cerioni, Giovanni; Cocco, Maria Teresa; Maccioni, Antonio; Plumitallo, Antonio, Journal of Heterocyclic Chemistry 1982, 19, 135-139) was dissolved in dry tetrahydrofuran (12 mL), cooled to −70° C., treated in portions with n-BuLi (2.5 M; 1.9 mL, 4.8 mmol) and stirred at −70° C. for 30 min. 4,4,5,5-Tetramethyl-1,3,2-dioxaborolane (900 mg, 4.8 mmol) was added and stirring was continued for 1.5 h during which the temperature rose to −30° C. The mixture was treated with saturated NH4Cl (5 mL) and extracted with ethyl acetate (2×25 mL). The combined extracts were washed with saturated NaCl (10 mL), dried (Na2SO4) and evaporated to give the title compound which was used without further purification (1.2 g, 99%): 1H NMR (400 MHz, CDCl3) δ 7.62 (d, J=1.1 Hz, 1H), 7.48 (dd, J=8.0, 1.3 Hz, 1H), 6.82 (d, J=8.1 Hz, 1H), 5.69 (s, 2H), 1.32 (s, 12H); EIMS m/z 264.

Source