Production method for 2-fluoro-4-borono-l-phenylalanine, and precursor of 2-fluoro-4-borono-l-phenylalanine

A method for producing a compound represented by the following formula:

• (where X represents F or 18F;
• R30 represents hydrogen or a protecting group PG1 for a carboxyl group;
• R40 or R50 independently represents hydrogen or a protecting group PG2 for an amino group, or NR40R50 are combined together to form C6H5(C6H5)C═N;
• and R15 and R16 are combined together with a boron atom to form a ring serving as a protecting group for boron atom, comprising:
• reacting a compound represented by the following formula:
• where R1 represents a bromo group, an iodo group, a chloro group, a nitro group, or an amino group;
• R2 represents a halogen group, a nitro group, an amino group, Sn(R6)3, N═N—NR7R8, OSO2R9, NR10R11, substituted or unsubstituted phenyl iodo, a substituted or unsubstituted heterocyclic iodo group, or boric acid or a boric ester (where R6 represents an alkyl group having 1 to 7 carbon atoms or a benzyl group;
• R7 and R8 are the same or different, each representing hydrogen, an alkyl group having 1 to 7 carbon atoms, a halogen-substituted alkyl group having 1 to 7 carbon atoms, or an optionally substituted phenyl group, or else R7 and R8 are combined together with N to form a 3- to 7-membered cyclic structure;
• R9 represents an alkyl group having 1 to 7 carbon atoms, a halogen-substituted alkyl group having 1 to 7 carbon atoms, or an optionally substituted phenyl group;
• R10 and R11 are the same or different, each representing an alkyl group having 1 to 7 carbon atoms, a halogen-substituted alkyl group having 1 to 7 carbon atoms, or an optionally substituted phenyl group, or else R10 and R11 are combined together with N to form a 3- to 7-membered cyclic structure);
• and R30, R40, and R50 have the same meaning as described above,
• wherein said reacting comprises radiating said compound in the presence of a catalyst and a ligand.