Premium
Synthesis of 4‐(2‐chlorophenyl)‐1, 6‐dihydro‐1, 3, 9‐trimethylimidazo[1, 2‐ a ]pyrazolo[4, 3‐f] [1, 4]diazepine‐9‐ 14 C (CI‐918‐ 14 C)
Author(s) -
Hicks James L.,
Huang C. C.,
Goel Om P.,
Butler Donald E.
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.2580211008
Subject(s) - chemistry , diazepine , yield (engineering) , medicinal chemistry , amine gas treating , hydrolysis , chloride , acetyl chloride , stereochemistry , organic chemistry , ring (chemistry) , catalysis , materials science , metallurgy
4‐(2‐Chlorophenyl)‐1, 6‐dihydro‐1,3,9‐trimethylimidazo[1,2‐ a ]pyrazolo‐[4,3‐ f ] [1,4]diazepine‐9‐ 14 C (CI‐918‐ 14 C) was made starting with acetyl‐1‐14C chloride. An efficient synthesis of 1‐chloro‐2‐propanone‐2‐ 14 C was developed as a precursor to 2‐methyl‐1,3‐dioxolane‐2‐ 14 C‐2‐methanamine. The latter reacted with 4‐(2‐chlorophenyl)‐1,6‐dihydro‐1,3‐dimethylpyrazolo[3,4‐ e ] [1,4]diazepine‐7‐thione to yield 4‐(2‐chlorophenyl)‐1,6‐dihydro‐1, 3‐dimethyl‐N‐[(2‐methyl‐1,3‐dioxolan‐2‐yl‐2‐ 14 C)methyl] pyrazolo[3,4‐ e ] [1,4]diazepin‐7‐amine. Hydrolysis and cyclization gave the title compound. The six‐step reaction sequence gave an overall radiochemical yield of 19%. The product had a specific activity of 8.31 mCi/mmol.