Phosphoric acid ester production method

A method for producing a phosphoric acid ester, comprising:

• a step (1):
• a step of allowing phosphorus oxytrihalide represented by Formula (I)
• [Chemical Formula 18]
• (wherein X is halogen)
• to react with a phenol compound or naphthol compound represented by Formula (II)
• [Chemical Formula 19]
• (wherein R1, R2, R3, R4 and R5 are independent from one another, and are a hydrogen atom, a straight or branched-chain C1-6 alkyl group, or a C6-12 aryl group which may be substituted with a straight or branched-chain C1-4 alkyl group, and alternatively R1 and R2, R2 and R3, R3 and R4, or R4 and R5 may form a 6-membered ring together with the carbon atoms of the benzene ring to which these groups are bound, provided that R1, R2, R3, R4 and R5 are not hydrogen atoms at the same time), at a molar ratio of 1.1-3.0:1 in the presence of a metal halide, to produce a mono-substituted phosphorodihalidate represented by Formula (III)
• [Chemical Formula 20A]
• (wherein X, R1, R2, R3, R4 and R5 have the same meaning as the above-described meaning);
• and
• a step (2):
• a step of allowing the mono-substituted phosphorodihalidate obtained in the step (1) represented by the Formula (III)
• [Chemical Formula 20B]
• to react with a diol compound represented by Formula (IV)
• [Chemical Formula 21]
• (wherein R6 and R7 are independent from each other, and are a hydrogen atom, a straight or branched-chain C1-6 alkyl group, or a C6-12 aryl group which may be substituted with a straight or branched-chain C1-4 alkyl group) so as to perform a dehydrohalogenation reaction to produce a phosphorus compound represented by Formula (V)
• [Chemical Formula 22]
• (wherein R1, R2, R3, R4, R5, R6 and R7 have the same meaning as the above-described meaning).