Patent ID: 8501965

Claim:
A method for producing a compound represented by the general formula (7) or it's enantiomer, or their salts, comprising step 1: (Step 1) a process of fluorinating a compound represented by the general formula (6) or it's enantiomer using a nucleophilic fluorinating agent and an organic base having an amidine or guanidine structure, [wherein, in the general formula (6), PG 1 represents a protecting group for an amino group, R 1 represents a C1 to C6 alkyl group which may be substituted or a C3 to C8 cycloalkyl group which may be substituted, and Ns represents a 2-nitrobenzenesulfonyl group or a 4-nitrobenzenesulfonyl group], [wherein, in the general formula (7), PG 1 represents a protecting group for an amino group, R 1 represents a C1 to C6 alkyl group which may be substituted or a C3 to C8 cycloalkyl group which may be substituted, and Ns represents a 2-nitrobenzenesulfonyl group or a 4-nitrobenzenesulfonyl group].