2-(2-BROMOPHENYL)-1,3-DIOXOLANE

Clear colorless to pale yellow liquid

To a solution of 2-bromobenzaldehyde (5.30 mmol) in benzene (40 mL) was added ethylene glycol (1.26 mL, 22.6 mmol, 4.3 eq) and p-toluenesulfonic acid (70 mg, 0.37 mmol, 0.07 eq). The resulting mixture was heated at reflux in a Dean-Stark apparatus. After 4 h, the reaction was cooled to ambient temperature, quenched with triethylamine, and concentrated in vacuo. Purification was accomplished with chromatography on silica gel. Quantitative yield.(181-1) (181-1) This was a modified procedure according to literature.Toluene (1 L), 2-bromobenzaldehyde (190 g, 1.05 mole) and ethylene glycol (76 ml, 1.3 mole) were heated to reflux with azeotropical distillation of water (-‘10 h). 600 ml of toluene was distilled off and the residual solution was cooled to RT and washed with sat. NaHCO3 solution (200 ml), water (200 ml), dried over Na2SO4, and evaporated under reduced pressure. The crude compound was distilled under high vacuum. 190 g (82percent) of 2-(2-bromophenyl)-1, 3-dioxolane as a colorless liquid was received, purity by GC: 98percent.In a 100 mL two-necked flask, 4.97 g (26.9 mmol) of 2-bromobenzaldehyde, 3.49 g (56.2 mmol) of ethylene glycol and 470 mg (2.47 mmol) of p-toluenesulfonic acid monohydrate were added, 10 mL of benzene was added, and the resulting mixture was refluxed with a Dean-Stark apparatus for 24 hours. After cooling to room temperature, the reaction was terminated with saturated aqueous sodium hydrogen carbonate solution, and extracted with dichloromethane. The organic layer was dried with sodium sulfate, and the solvent was distilled off under reduced pressure to obtain a crude product. The crude product was purified by silica gel column chromatography (dichloromethane) to obtain 5.01 g (22.1 mmol) of 2- (2-bromophenyl)-1, 3-dioxolane in a yield of 82percent. The measurement results of NMR are shown below.A solution of 2-bromobenzaldehyde (12a, 37.1 g, 0.20 mol), ethylene glycol (50 mL, 55.6 g, 0.90 mol) and p-toluenesulfonic acid (1.0 g, 0.005 mol) in toluene (200 mL) was refluxed in a Dean-Stark apparatus (bp 118-120 °C) in a microwave reactor under irradiation with a constant 650 W energy for 2 h.Example 4 C.

Molecular Weight:229.07
XLogP3:2
Hydrogen Bond Acceptor Count:2
Rotatable Bond Count:1
Exact Mass:227.97859
Monoisotopic Mass:227.97859
Topological Polar Surface Area:18.5
Heavy Atom Count:12
Complexity:146
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes