Trifluoroacetic acid → 4-Amino-1-(2-chloropyrimidin-4-yl)-4-methylpiperidine

Participants

Reaction Steps

The procedure described in Example 2 is followed up to the end of step (c). A solution of 6.81 g (0.021 mol) of 4-t-butoxycarbonylamino-1-(2-chloropyrimidin-4-yl)-4-methylpiperidine (step c) in 80 ml of anhydrous methylene chloride is cooled under a nitrogen atmosphere and 16.4 ml of anisole and 83 ml of trifluoroacetic acid are added slowly. The mixture is stirred for 1 hour at room temperature and 80 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 to give 4-amino-1-(2-chloropyrimidin-4-yl)-4-methylpiperidine as the base, which is treated with maleic acid in an ethanol/ethyl ether mixture. The maleate obtained in this way is isolated by filtration (yield 65%, m.p. 125°-126° C.).

Provenance & Evidence