Reaction #1252

Reaction equation

anisole

trifluoroacetic acid

4-t-butoxycarbonylamino-1-(4-chloropyrimidin-2-yl)-4-methylpiperidine

NaOH

→

4-amino-1-(4-chloropyrimidin-2-yl)-4-methylpiperidine

Solvents

methylene chloride

Conditions

Workup

1. 1
   ExtractionThe reaction medium is extracted with methylene chloride
2. 2
   Dryingdried over Na2SO4
3. 3
   Otherthe solvent and the anisole are evaporated off under reduced pressure
4. 4
   OtherThe residue is purified by chromatography

Procedure

A solution of 2.22 g (0.0068 mol) of 4-t-butoxycarbonylamino-1-(4-chloropyrimidin-2-yl)-4-methylpiperidine (step c) in 25 ml of anhydrous methylene chloride is cooled under a nitrogen atmosphere and 5 ml of anisole and 25 ml of trifluoroacetic acid are added slowly. The mixture is stirred for 1 hour at room temperature and 25 ml of a 30% solution of NaOH are added slowly. The reaction medium is extracted with methylene chloride and dried over Na2SO4 and the solvent and the anisole are evaporated off under reduced pressure. The residue is purified by chromatography using CH2Cl2 /MeOH=9/1 as the eluent to give 4-amino-1-(4-chloropyrimidin-2-yl)-4-methylpiperidine as the base, which is treated with maleic acid in an ethanol/isopropyl ether mixture. The maleate obtained in this way is isolated by filtration (m.p. 154°-155° C.).

Source