Purification method of aldehyde compound

A manufacturing method of an aldehyde compound, comprising:

• a step of obtaining a reaction solution containing an aldehyde compound by reacting a compound represented by the following Formula (a1) or (a2) with hydrogen and carbon monoxide in the presence of a metal compound of groups 8 to 10 and a phosphorus compound;
• a step of neutralizing the reaction solution by adding water and a base compound to the reaction solution;
• and
• a step of purifying an aldehyde compound by distilling the neutralized reaction solution,
• wherein the phosphorus compound is represented by the following Formula (R1O)3P, and the base compound is at least one selected from carbonate and hydrogen carbonate of metals of group I on the periodic table and carbonate and hydrogen carbonate of metals of group II on the periodic table,
• in Formula (a1), X represents a hydrogen atom, a cyano group, an aldehyde group, or a —CH═NR group;
• R represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an aryl group;
• and in Formulae (a1) and (a2), n represents 0, 1, or 2,
• (R1O)3P
• in the formula, a plurality of R1s may be the same as or different from each other, and represents an alkyl group having 1 to 16 carbon atoms that may have a substituent or an aryl group having 6 to 16 carbon atoms that may have a substituent, and
• wherein the step of neutralizing the reaction solution is performed within a temperature range of equal to or higher than 40° C. and equal to or lower than 50° C.