Reaction #58827

Reaction equation

ethynyl(trimethyl)silane

2-(3-bromophenyl)-1,3-dioxolane

N,N-dimethylformamide

triethylamine

→

{[3-(1,3-dioxolan-2-yl)phenyl]ethynyl}-(trimethyl)silane

Yield 74.9%

Solvents

water

Conditions

Workup

1. 1
   Otherwas bubbled with anhydrous argon for 5 minutes
2. 2
   Temperaturecooled to room temperature
3. 3
   Extractionextracted with ethyl ether
4. 4
   Dryingdried over MgSO4
5. 5
   Concentrationconcentrated in vacuo

Procedure

A mixture of ethynyl(trimethyl)silane (36 g, 367 mmol), 2-(3-bromophenyl)-1,3-dioxolane (78 g, 342 mmol), N,N-dimethylformamide (400 mL), and triethylamine (1.1 81 mL, mmol) was bubbled with anhydrous argon for 5 minutes, treated with copper iodide (0.94 g, 4.96 mmol) and dichlorobis(triphenylphosphine) palladium(II) (7.7 g, 11.01 mmol), stirred at 60° C. for 3 hours, cooled to room temperature, poured into water and extracted with ethyl ether. The organic extracts were combined, dried over MgSO4 and concentrated in vacuo to give {[3-(1,3-dioxolan-2-yl)phenyl]ethynyl}-(trimethyl)silane as a yellow oil (63 g, 256 mmol). The yellow oil was dissolved in MeOH (600 mL) and CH2Cl2 (600 mL), treated with cesium carbonate (91.8 g, 281.6 mmol), stirred at room temperature for 10 h, poured into water and extracted with ethyl ether. The ether extracts were combined, dried over MgSO4, concentrated in vacuo and distilled to give 2-(3-ethynylphenyl)-1,3-dioxolane as a yellow oil (42 g, 71% yield), MS m/e M+ 174; 1H NMR (400 MHz, DMSO-d6) 3.9-4.05 (m, 4H), 4.15 (s, 1H), 5.7 (s, 1H), 7.35-7.45 (m, 4H).

Source