A method for synthesizing a compound having the formula or a racemic mixture thereof, wherein: X is selected from the group consisting of: and or a racemic mixture thereof; and Y is represented by the formula: comprising the steps of: a. mixing a pterin derivative compound and X in the presence of (-(7-azabenzotriazol-1 -yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate (HATU), Hunig's base (DIPEA) and a polar solvent; b. adding a resulting product to TFA:TIPS:H 2 O (95:2.5:2.5) solvent to form a suspension; c. cannulating the suspension as a steady stream to methyl tertiary-butyl ether (MTBE) to precipitate an intermediate compound; d. filtering and washing the intermediate compound precipitate with methyl tertiary-butyl ether (MTBE); e. drying the intermediate compound solution under high vacuum conditions; f. suspending the resulting intermediate compound with water; g. adding aqueous sodium hydroxide (NaOH) to adjust the pH; h. mixing the aqueous solution with Y and water to obtain a resulting mixture in an oil bath; i. cooling the resulting mixture to room temperature; j. adding the resulting mixture to a stirred acetone to give a precipitate Pteroyl-amino acid-fluorescent dye compound; and k. precipitating the Pteroyl-amino acid-fluorescent dye compound under high vacuum conditions. X is selected from the group consisting of: and or a racemic mixture thereof; and Y is represented by the formula: comprising the steps of: a. mixing a pterin derivative compound and X in the presence of (-(7-azabenzotriazol-1 -yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate (HATU), Hunig's base (DIPEA) and a polar solvent; b. adding a resulting product to TFA:TIPS:H 2 O (95:2.5:2.5) solvent to form a suspension; c. cannulating the suspension as a steady stream to methyl tertiary-butyl ether (MTBE) to precipitate an intermediate compound; d. filtering and washing the intermediate compound precipitate with methyl tertiary-butyl ether (MTBE); e. drying the intermediate compound solution under high vacuum conditions; f. suspending the resulting intermediate compound with water; g. adding aqueous sodium hydroxide (NaOH) to adjust the pH; h. mixing the aqueous solution with Y and water to obtain a resulting mixture in an oil bath; i. cooling the resulting mixture to room temperature; j. adding the resulting mixture to a stirred acetone to give a precipitate Pteroyl-amino acid-fluorescent dye compound; and k. precipitating the Pteroyl-amino acid-fluorescent dye compound under high vacuum conditions. a. mixing a pterin derivative compound and X in the presence of (-(7-azabenzotriazol-1 -yl)-N,N,N',N'-tetramethyluronium hexafluorophosphate (HATU), Hunig's base (DIPEA) and a polar solvent; b. adding a resulting product to TFA:TIPS:H 2 O (95:2.5:2.5) solvent to form a suspension; c. cannulating the suspension as a steady stream to methyl tertiary-butyl ether (MTBE) to precipitate an intermediate compound; d. filtering and washing the intermediate compound precipitate with methyl tertiary-butyl ether (MTBE); e. drying the intermediate compound solution under high vacuum conditions; f. suspending the resulting intermediate compound with water; g. adding aqueous sodium hydroxide (NaOH) to adjust the pH; h. mixing the aqueous solution with Y and water to obtain a resulting mixture in an oil bath; i. cooling the resulting mixture to room temperature; j. adding the resulting mixture to a stirred acetone to give a precipitate Pteroyl-amino acid-fluorescent dye compound; and k. precipitating the Pteroyl-amino acid-fluorescent dye compound under high vacuum conditions.