Patent ID: 8168809
Filing Date: 2012-05-01
Classification: C07D

Abstract:
1. A method for producing 2-methyl-3-(3,4-methylenedioxyphenyl) propanal comprising: Step (1): carrying out a process (A) for reacting 1,2-methylenedioxybenzene represented by the following formula (1) with 2-methyl-3,3-diacetoxypropene represented by the following formula (2) or a process (B) for reacting 1,2-methylenedioxybenzene, methacrolein and acetic anhydride, thereby providing a reaction mixture containing 1-acetoxy-2-methyl-3-(3,4-methylenedioxyphenyl)-1-propene represented by the following formula (3); Optionally Step (2), removing a compound having a boiling point higher than 1-acetoxy-2-methyl-3-(3,4-methylenedioxyphenyl)-1-propene from the reaction mixture containing 1-acetoxy-2-methyl-3-(3,4-methylenedioxyphenyl)-1-propene, thereby providing a crude product containing 1-acetoxy-2-methyl-3-(3,4-methylenedioxyphenyl)-1-propene; Step (3): providing a reaction mixture containing 2-methyl-3-(3,4-methylenedioxyphenyl)propanal represented by the following formula (4) by hydrolysis reaction or ester exchange reaction with an alcohol of subjecting 1-acetoxy-2-methyl-3-(3,4-methylenedioxyphenyl)-1-propene represented by the formula (3) obtained in the step (1); Optionally Step (4), removing a compound having a boiling point higher than 2-methyl-3-(3,4-methylenedioxyphenyl)propanal from the reaction mixture, thereby providing a crude product containing 2-methyl-3-(3,4-methylenedioxyphenyl)propanal; Step (5): purifying by distillation of the reaction mixture obtained in the step (3) carrying optionally Step (6): carrying out purification by distillation in the step (5) at a liquid temperature in a distillation vessel of 210° C. or less; and optionally Step (7), carrying out washing, and neutralization or neutralization and adsorption; whereby the process shall comprise at least one of optional steps (2), (4) (6) and (7).