Process for synthesizing anhydroecgonine derivative

A process for synthesizing a phenyltropane compound represented by the formula (4):

• wherein R3 is a group selected from the group consisting of an unsubstituted alkyl group, a substituted alkyl group, an unsubstituted aralkyl group, a substituted aralkyl group and a chelating group capable of forming a complex together with a radioactive transition metal;
• R4 is a group selected from the group consisting of an alkyl ester group and a chelating group capable of forming a complex together with a radioactive transition metal;
• L is a methylene chain of 1 to 4 carbon atoms as a connecting portion;
• n′ and n″ are independently an integer of 1 or 0;
• and X is a hydrogen atom, an alkyl group, an alkoxy group, or a halogen atom or its radioisotope, which comprises reacting an anhydroecognine intermediate compound of the following formula (3) with substituted or unsubstituted phenylmagnesium bromide, wherein the compound of formula (3) is obtained by a process which comprises reacting a cycloheptatriene compound represented by the formula (1):
• wherein n is an integer of 0 or 1;
• and R1 is a cyano group in the case of n being 0, and R1 is selected from an alkyl group and a C7-10 aralkyl group in the case of n being 1, with a primary amine represented by the formula (2):
• R2NH2 (2)
• wherein R2 is a hydrogen atom, an unsubstituted alkyl group, a substituted alkyl group, an unsubstituted C7-10 aralkyl group or a substituted C7-10 aralkyl group, or a salt thereof or ammonia in the presence of a base to obtain an anhydroecgonine compound represented by the formula (3):
• wherein R1 and R2 as defined above.