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Synthesis of racemic [3‐ 11 C]‐labelled alanine, 2‐aminobutyric acid, norvaline, norleucine, leucine and phenylalanine and preparation of L‐[3‐ 11 C]alanine and L‐[3‐ 11 C]phenylalanine
Author(s) -
Antoni Gunnar,
Långström Bengt
Publication year - 1987
Publication title -
journal of labelled compounds and radiopharmaceuticals
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.432
H-Index - 47
eISSN - 1099-1344
pISSN - 0362-4803
DOI - 10.1002/jlcr.2580240203
Subject(s) - chemistry , norleucine , norvaline , phenylalanine , alanine , racemization , amino acid , enantiomer , d amino acid oxidase , strecker amino acid synthesis , leucine , stereochemistry , organic chemistry , oxidase test , enantioselective synthesis , enzyme , catalysis , biochemistry
The syntheses of racemic [3‐ 11 C]‐labelled alanine, 2‐amino‐butyric acid, norvaline, norleucine, leucine and phenyl‐alanine are reported. The reaction were performed by a phase‐transfer alkylation reaction on N ‐(diphenylmethylene)‐glycine tert ‐butyl ester with the appropriate 11 C‐alkyl iodides followed by acidic hydrolysis and the labelled amino acids were obtained in 10‐55 % radiochemical yield. L‐[3‐ 11 C]‐Alanine and L‐[3‐ 11 C]phenylalanine were obtained in 99 % enantiomeric excess after treatment of the corresponding racemic mixture by D‐amino acid oxidase immobilized on glutaral‐dehyde‐activated glass beads. In a typical run starting with 120 mCi [ 11 C]carbon dioxide, 25 mCi [1‐ 11 C]benzyl iodide was prepared and used to give 6 mCi of DL‐[3‐ 11 C]phenylalanine within 50 minutes. Following treatment with D‐amino acid oxidase, 0.3 mCi of L‐[3‐ 11 C]phenylalanine was obtained after a total synthesis time of about 100 minutes.