Phosphorus oxychloride → 2,5-Dimethoxy-4-methylbenzaldehyde

Beteiligte Stoffe

Reaktionsschritte

A solution of 40 ml. phosphorous oxychloride (POCl3) and 45 ml. of N-methylformanilide is allowed to stand at ambient temperature for 50 minutes. There is then added 15.2 g. of 2,5-dimethoxytoluene and the resulting solution is heated on the steam bath for 140 minutes. The extremely dark viscous reaction mixture is added to 2 liters of water, and allowed to stir for several hours to complete the hydrolysis of the reaction intermediates. The solid product is removed by filtration, and after washing with water and air-drying yields 16.6 g of reddish crumbly crystals. This solid product is extracted with 2×125 ml. of boiling hexane, which on cooling deposits 12.1 g. of pale cream-colored crystals. Recrystallization from boiling hexane, yields a brilliant white product 2,5-dimethoxy-4-methylbenzaldehyde.

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