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Synthesis of 4‐tert‐butyl‐3‐(2‐chloro ‐[‐2‐ 14 C]ethyl)ureido benzene
Author(s) -
Azim Elmostafa,
Dupuy JeanMichel,
Maurizis JeanClaude,
Gaudreault René C.,
Veyre Annie,
Madelmont JeanClaude
Publication year - 1997
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/(sici)1099-1344(199707)39:7<559::aid-jlcr4>3.0.co;2-3
Subject(s) - chemistry , diazomethane , curtius rearrangement , sodium azide , medicinal chemistry , hydrolysis , yield (engineering) , organic chemistry , benzene , potassium carbonate , ethanol , nuclear chemistry , materials science , metallurgy
Carbonation of CH 3 MgI with 14 CO 2 led to sodium [1‐ 14 C] acetate 1 which was successively brominated and esterifed with diazomethane to give rise to methyl 2‐bromo‐[‐1‐ 14 C] acetate: 3 , the reduction of which with H 3 Al gave 2‐bromo‐[‐1‐ 14 C]ethanol 4 . 4 was then reacted with NaCN; the intermediate 3‐hydroxy‐[‐3‐ 14 C]propionitrile 5 was hydrolyzed with HCl at 130° C into the corresponding acid: 6 which was transformed into 3‐chloro‐[‐3‐ 14 C] propionyl chloride: 7 . 7 reacted with NaN 3 gave 3‐chloro‐[‐3‐ 14 C ] propyl azide: 8 which by Curtius rearrangement led to 2‐chloro‐[‐2‐ 14 C ] ethyl isocyanate: 9 which finally was condensed with 4‐t‐butylaniline leading to the title compund (radiochemical purity 99%) in an overall yield of about 10% based on [ 14 C ] barium carbonate. © 1997 John Wiley & Sons, Ltd.