Abstract: Provided is a method of manufacturing a high quality phosphonocrotonic acid derivative. The present invention is a method of manufacturing a compound represented by the following Formula (3) by reacting a compound represented by the following Formula (1) with a compound represented by the following Formula (2), which comprises a treatment process using an acid or base. [in the formula, R1 represents a C1-6 linear or branched alkyl group that may be substituted by a C6-10 aryl group, a C2-6 linear or branched alkenyl group that may be substituted by a C6-10 aryl group, a C2-6 linear or branched alkynyl group that may be substituted by a C6-10 aryl group, or a C6-10 aryl group, R2 represents a hydrogen atom, or a C1-6 linear or branched alkyl group that may be substituted by a C6-10 aryl group, R3 represents a C1-6 linear or branched alkyl group, a C6-10 aryl group, or a halogen atom, and X represents a halogen atom, and multiple R1s may be the same or different].

Abstract: Provided is a method of manufacturing a high quality phosphonocrotonic acid derivative. The present invention is a method of manufacturing a compound represented by the following Formula (3) by reacting a compound represented by the following Formula (1) with a compound represented by the following Formula (2), which comprises a treatment process using an acid or base. [in the formula, R1 represents a C1-6 linear or branched alkyl group that may be substituted by a C6-10 aryl group, a C2-6 linear or branched alkenyl group that may be substituted by a C6-10 aryl group, a C2-6 linear or branched alkynyl group that may be substituted by a C6-10 aryl group, or a C6-10 aryl group, R2 represents a hydrogen atom, or a C1-6 linear or branched alkyl group that may be substituted by a C6-10 aryl group, R3 represents a C1-6 linear or branched alkyl group, a C6-10 aryl group, or a halogen atom, and X represents a halogen atom, and multiple R1s may be the same or different].

Abstract: A safe and effective solid radiographic contrast medium which comprises an iodine-substituted aromatic polymer with an iodine content of 1 to 75% by weight and which is free of side effects on the digestive system such as constipation as found in barium preparations and which has no risk of causing iodine shocks as found in aqueous iodine preparations containing meglumine sodium amidotrizoate.

Abstract: A method for rendering a flammable polymer material flame-resistant, which comprises incorporating to the flammable polymer material a powder of a cross-linked aromatic polymer brominated to contain from 30 to 70% by weight of bromine.