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Synthesis of 14 C‐labeled and 2 H‐labeled dibucaine
Author(s) -
Chaudhuri Naba K.
Publication year - 1985
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.2580220204
Subject(s) - chemistry , dibucaine , chloroacetyl chloride , quinoline , medicinal chemistry , acetic anhydride , ethylenediamine , nuclear chemistry , chloride , organic chemistry , catalysis
A synthesis of dibucaine labeled with 14 C in the heterocyclic ring is described. The synthesis was accomplished in five steps starting with isatin and acetic anhydride‐2‐ 14 C as shown in Scheme I. Two deutero analogs, dibucaine‐d 2 and dibucaine‐d 9 , were also synthesized by the reactions shown in Scheme II. Dibucaine‐d 9 , was synthesized by condensation of 2‐chloro‐N‐[2‐(diethylamino)ethyl]‐4‐quinoline carboxamide with sodium salt of n‐butyl‐d 9 alcohol. Dibucaine‐d 2 was synthesized by condensation of 2‐chloroquinoline carboxylic acid chloride with N,N‐diethyl dideutero‐ethylenediamine (prepared from chloroacetyl chloride) followed by reaction with sodium n‐butoxide. 14 C‐labeled dibucaine was found to undergo considerable radiolysis on storage to give 2‐butoxy‐quinoline‐4‐carboxamide as a major decomposition product.