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The synthesis of oxygen‐18 enriched phenol and naphthol from 18 O 2
Author(s) -
Walker T. E.,
Goldblatt M.
Publication year - 1984
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.2580210410
Subject(s) - chemistry , phenol , yield (engineering) , reagent , oxygen , phenols , naphthalene , alcohol , organic chemistry , halide , bromobenzene , aryl , medicinal chemistry , catalysis , materials science , metallurgy , alkyl
Phenols enriched with oxygen‐18 can be synthesized using an acid exchange reaction in H 2 18 O at elevated temperature, however, to obtain highly enriched products very large quantities of water must be used and recycled. Grignard reagents will react readily with oxygen gas with almost no isotopic dilution to produce the 18 O enriched alcohol or phenol. Aromatic Grignards do not produce as high a yield as the aliphatic Grignards, however, both provide convenient routes to labeled products. The yield of naphthol from an aryl halide can be improved by the addition of an aliphatic halide (which produces the alcohol as a by product), however, the yield of naphthol from 18 O 2 gas is not improved by this approach. Either 1‐bromo‐naphthalene or bromobenzene was converted into the Grignard reagent and reacted with oxygen‐18 enriched gas at 0° in a sealed reaction system. The reaction was worked up in the conventional manner and the yields from 18 O 2 were 34% for [ 18 O] phenol and 23% for 1‐[ 18 O]naphthol.