Method for producing ϵ-caprolactam

A method of producing 5-cyanovaleramide through adipamide as an intermediate, the method comprising converting adipamide, formed from a material compound, to 5-cyanovaleramide in the presence of a metal oxide and a solvent, wherein the metal oxide an oxide of one or more metallic elements selected from the group consisting of metallic elements of group 5 and groups 7 to 14 in the 4th to 6th periods of the periodic table,

• wherein said material compound is a carboxylic acid represented by the following Formula (I) or (II):
• wherein
• in Formula (I) and Formula (II), R′, R2, and R3 each independently represent a hydrogen atom (H) or an alkyl group having 1 to 6 carbon atoms;
• in Formula (I), X represents —CH2—CH2—CH2—CH2—, —CH2—CH2—CH═CH—, —CH2—CH═CH—CH2—, —CH═CH—CH═CH—, —CH2—CH2—CH2—CH(OH)—, —CH2—CH2—C(OH)H—CH2—, —CH═CH—C(OH)H—CH2—, —C(OH)H—CH2—CH═CH—, or —CH2—CH═CH—CH(OH)—;
• and,
• in Formula (II), Y represents —CH2—CH2— or —CH═CH—, or a salt or an ester thereof, or a mixture thereof;
• and
• wherein said oxide of one or more metallic elements constitutes only said oxide of said metallic element, or said oxide of one or more metallic elements is in the form of a composite metal oxide in which the oxide of said metallic element covers the surface of an oxide of a metallic element other than said metallic element wherein the ratio of said oxide of said metallic element in said composite metal oxide is 2% by weight to 80% by weight.