3-methoxy-4-(2-methylpropoxy)benzaldehyde

Conditions: temp:20.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: The synthesis is carried out in argon condition. 2.2 g (11.8 mmol) of N-Boc-piperazine and 2.5 g (about 12 mmol) of crude 4-(2-methylpropyloxy)-3-methoxybenzaldehyde are mixed in 50 ml of dry of dichloromethane. After dissolution 2 drops of acetic acid is added, then 4.25 g (20 mmol) of NaBH(OAc)3 is added and the mixture is stirred for 12 h at 20° C. Then 20 ml of 5% NaHCO3 aqueous solution is added dropwise with care to the reaction mixture. The organic layer is separated, washed with 5% Na2CO3 solution, dried over sodium sulfate, filtered off, concentrated in vacuum at 50÷80° C. The residue (3.3 g of oil)-crude N-(tert-butyloxycarbonyl)-N′-(4-(2-methylpropyloxy)-3-methoxybenzyl)piperazine is used on the next step without further purification. of dry of dichloromethane After dissolution 2 drops of acetic acid is added The organic layer is separated washed with 5% Na2CO3 solution dried over sodium sulfate filtered off concentrated in vacuum at 50÷80° C The residue (3.3 g of oil)-crude N-(tert-butyloxycarbonyl)-N′-(4-(2-methylpropyloxy)-3-methoxybenzyl)piperazine is used on the next step without further purification

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: In 250 ml three necked flask, equipped with reflux condenser, mechanical stirrer, 30.4 g (200 mmol) of vanillin, 28 g (200 mmol) of dry K2CO3 and 150 ml of abs. dimethylformamide are placed in the flow of argon. The mixture is stirred for 20 min in argon condition, then 34.3 g (250 mmol) of isobutyl bromide is added. The mixture is refluxed with stirring in argon condition for 20 h at 90÷100° C., and concentrated in vacuum at 50÷80° C. to dryness. Then 200 ml of water is added to the residue, the mixture is extracted with (4×100 ml) of dichloromethane. The combined organic fraction is washed with 7% NaOH solution, dried over magnesium sulfate, filtered off, concentrated in vacuum at 50÷80° C. The residue (15 g of brown oil)-crude 4-(2-methylpropyloxy)-3-methoxybenzaldehyde is used on the next step without further purification. with reflux condenser, mechanical stirrer The mixture is refluxed with stirring in argon condition for 20 h at 90÷100° C. concentrated in vacuum at 50÷80° C. to dryness Then 200 ml of water is added to the residue the mixture is extracted with (4×100 ml) of dichloromethane The combined organic fraction is washed with 7% NaOH solution dried over magnesium sulfate filtered off concentrated in vacuum at 50÷80° C The residue (15 g of brown oil)-crude 4-(2-methylpropyloxy)-3-methoxybenzaldehyde is used on the next step without further purification