Method for producing peptide thioester

A method for producing a thioester of a peptide or a glycopeptide, which comprises:

• (1) a step of allowing a peptide or glycopeptide having a protected amino group at the N-terminus and a carboxyl group at the C-terminus to react with a compound represented by the formula R—SO2—N═C═O (wherein R represents an alkyl group containing 1 to 10 carbon atoms, or an aryl group that may have a substituent) in the presence of a base, so as to synthesize a peptide or glycopeptide having a protected amino group at the N-terminus and —CONH—SO2—R (wherein R has the same definitions as described above) at the C-terminus;
• (2) a step of allowing a peptide or glycopeptide having a protected amino group at the N-terminus and —CONH—SO2—R (wherein R has the same definitions as described above) at the C-terminus to react with a compound represented by the formula Hal-CH2—X (wherein Hal represents a halogen atom, and X represents a hydrogen atom, —CN, or —CO2R1 wherein R1 represents an alkyl group containing 1 to 10 carbon atoms) in the presence of a base, or allowing the aforementioned peptide or glycopeptide to react with trimethylsilyldiazomethane or Me3O•BF4, so as to synthesize a peptide or glycopeptide having a protected amino group at the N-terminus and —CON(CH2X)—SO2—R (wherein X and R have the same definitions as described above) at the C-terminus;
• and
• (3) a step of allowing a peptide or glycopeptide having a protected amino group at the N-terminus and —CON(CH2X)—SO2—R (wherein X and R have the same definitions as described above) at the C-terminus to react with a compound represented by the formula Y—SH (wherein Y represents an alkyl group containing 1 to 10 carbon atoms, an alkenyl group containing 2 to 10 carbon atoms, an alkynyl group containing 2 to 10 carbon atoms, an aryl group, or a group formed by the combination thereof, and these groups may have a substituent) in the presence of a base, so as to synthesize a peptide or glycopeptide having a protected amino group at the N-terminus and —CO—S—Y (wherein Y has the same definitions as described above) at the C-terminus.