2-bromo-1,3,5-trimethylbenzene

反応条件: temp:0.00; pressure:0.00; stir:

反応条件: temp:0.00; pressure:0.00; stir:

反応条件: temp:0.00; pressure:0.00; stir:

反応条件: temp:0.00; pressure:0.00; stir:

反応条件: temp:0.00; pressure:0.00; stir:

反応条件: temp:0.00; pressure:0.00; stir:

反応条件: temp:0.00; pressure:0.00; stir:

反応条件: temp:0.00; pressure:0.00; stir:

反応条件: temp:0.00; pressure:0.00; stir:

反応条件: temp:0.00; pressure:0.00; stir:

反応条件: temp:-15.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: To a stirred solution of activated magnesium flakes (3.11 g, 0.128 mol) and a crystal of iodine, 2-bromomesitylene (23.40 g, 0.118 mol) in THF (80 cm3) was added dropwise at room temperature. The reaction was allowed to reflux for 3 hours. After the reaction mixture was cooled, it was added dropwise to an ether solution (80 cm3) of trimethoxyborane (26 cm3, 0.229 mol) at −15° C. The reaction stirred at −15° C. for 3 hours and then was warmed up to room temperature and left to stir overnight. The solution was then filtered under argon and the precipitated salts were washed with dry pentane (20 cm3). The filtrates were combined, concentrated and distilled under vacuum to give the desired dimethoxymesitylborane. 1H NMR (200 MHz, CDCl3) δ 2.28 (s, 6H), 2.30 (s, 3H), 3.58 (s, 6H), 6.84 (s, 2H). to reflux for 3 hours After the reaction mixture was cooled was warmed up to room temperature left to stir overnight The solution was then filtered under argon the precipitated salts were washed with dry pentane (20 cm3) concentrated distilled under vacuum

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: A solution of 2,4,6-trimethyl-1-bromobenzene (30.9 g, 155 mmol) in tetrahydrofuran (100 ml) is added slowly to magnesium turnings (3.77 g, 155 mmol), until the magnesium is just covered. A small quantity of iodine is added and the mixture is allowed to stand at room temperature for 25 minutes and then heated and stirred until the brown colour is lost. The remainder of the aryl bromide solution is added dropwise over a 20 minute period, with occasional heating to maintain the formation of the Grignard reagent solution. The reaction is stirred at room temperature for 1 hour. A solution of furfural (12.8 ml, 155 mmol) in tetrahydrofuran (70 ml) is added dropwise, and once the addition is complete, the reaction is stirred at room temperature for 2 hours. The reaction is quenched by cautious addition of excess saturated ammonium chloride solution, then extracted into ethyl acetate, washed with brine, dried over anhydrous magnesium sulfate, filtered and concentrated under reduced pressure. Purification by column chromatography on silica gel affords (2,4,6-trimethylphenyl)furan-2-ylmethanol. heated with occasional heating The reaction is stirred at room temperature for 1 hour once the addition the reaction is stirred at room temperature for 2 hours The reaction is quenched by cautious addition of excess saturated ammonium chloride solution extracted into ethyl acetate washed with brine dried over anhydrous magnesium sulfate filtered concentrated under reduced pressure Purification by column chromatography on silica gel