Varenicline Impurity 5 synthesis

Yield:950781-87-0 92.3%

Reaction Conditions:

with sodium hydroxide;water in acetonitrile at 70; for 3 h;

Steps:

4.4b

3-(Trifluoroacetyl)-8-nitro-2,3,4,5-tetrahydro-1 H-1,5-methano-3-benzazepin-7-amine (5.6g) was slurried in CH₃CN (56ml). A solution of NaOH (4.3g) in H₂O (40ml) was added. The mixture was warmed to 70⁰C and allowed to stir for 3 hours (the mixture remained a slurry the entire duration of reaction). After thin layer chromatography (eluent = 7:3 EtOAc:Hex) confirmed reaction completion, the product mixture was allowed to cool and granulate for 1 hour. The yellow-orange solids were filtered onto a No.2 Whatman filter paper and rinsed with H₂O. The solid was dried under a stream of N₂ overnight. This afforded 3.6g (92.3% yield) of a yellow-orange solid.

References:

WO2007/110730,2007,A2 Location in patent:Page/Page column 12