Pentamethylbenzene → 5,7-di-tert-butyl-3-(2,3,4,5,6-pentamethylphenyl)-3H-benzofuran-2-one

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Reaction Steps

11.5 g (77.5 mmol) of pentamethylbenzene and 10 ml (85.0 mmol) of tin tetrachloride are added to a solution of 19.7 g (75.0 mmol) of 5,7-di-tert-butyl-3-hydroxy-3H-benzofuran-2-one (compound (201), Table 2, Example 1a) in 50 ml of 1,2-dichloroethane and the reaction mixture is refluxed for 1 hour. The reaction mixture is diluted with water and extracted three times with toluene. The organic phases are combined, washed with water, dried over sodium sulfate and concentrated on a vacuum rotary evaporator. Crystallisation of the residue from ethanol yields 26.3 g (89%) of 5,7-di-tert-butyl-3-(2,3,4,5,6-pentamethylphenyl)-3H-benzofuran-2-one, m.p. 185°-190° C. (compound (111), Table 1).

Provenance & Evidence