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Molecules 2000, 5, M185

1,4-Bis(2',4',6'-trimethylphenylethynyl)benzene

Laura Jeffries and Eric Bosch*

Chemistry Department, Southwest Missouri State University, 901 South National Avenue, Springfield MO 65804, USA. E-mail: [email protected]

Received: 10 October 2000 / Accepted: 16 November 2000 / Published: 25 December 2000

The experimental procedure follows the general synthesis of arylalkynes reported by Sonogashira [1].

Thus a solution of 1,4-diiodobenzene (0.200 g, 0.60 mmol), 2-ethynylmesitylene (0.180 g, 1.24 mmol), bis(triphenylphosphine)palladium dichloride (0.035 g), copper iodide (0.020 g) and triphenylphosphine (0.077 g) in triethyl amine (20 mL) was refluxed under an argon atmosphere for 20 h [2,3]. The solvent was removed in vacuo and the solid residue partititioned between a (1:3) mixture of toluene and hexane (60 mL) and water (30 mL). The organic solvent was washed twice with water and then dried over magnesium sulfate. The solvents were removed in vacuo and the residue subjected to column chromatography with hexane as eluant to yield 0.163 g (75 %) of the title compound as fine white needles. The compound was recrystallized from ethanol.

M.p. 194-196 ^oC.

IR (KBr) 2920, 2201, 1615, 1510, 852, 833 cm^-1.

¹H NMR (200 MHz, CDCl₃): 2.30 (6H, s, CH₃), 2.48 (12H, s, CH₃), 6.91 (4H, s, Ar-H), 7.50 (4H, s, Ar-H).

¹³C NMR (200 MHz, CDCl₃): 20.84, 21.19, 89.18, 95.92, 119.89, 123.58, 127.79, 131.36, 138.18, 140.39.

Anal. Calcd. for C₂₈H₂₆, C: 92.77, H: 7.74. Found C: 92.51, H: 7.29.

Acknowledgements: The authors gratefully acknowledge financial support from Southwest Missouri State University.

References and Notes

1. Takahashi, S.; Kuroyama, Y, Sonogashira, K.; Hagihara, N. Synthesis 1980, 627.

2. 2-Ethynylmesitylene was prepared according to the general procedure in reference 1.

3. Full characterization of 2-ethynylmesitylene is reported in: Tinnenmans, A.H.A.; Laarhoven, W.H. Tetrahedron 1979, 35, 1537.

Sample availability: available from the authors and MDPI.