Trifluoroacetic acid → 1,3-Dibenzyl-1,4,8-triazaspiro[4,5]decan-2-one

Participants

Reaction Steps

Trifluoroacetic acid (68.5 g, 601 mmol) was added dropwise at 0° C. to a solution of tert-butyl 1,3-dibenzyl-2-oxo-1,4,8-triazaspiro[4,5]decane-8-carboxylate (13.5 g, 31.0 mmol) in CH2Cl2 (93 ml), and the mixture was stirred at this temperature for 15 min. After warming to RT, the reaction solution was stirred for a further 2.5 h. Subsequently, the reaction solution was adjusted to pH 7 to 8 using NaHCO3 solution, the organic phase was separated off, and the aqueous phase was extracted with CH2Cl2 (2×30 ml). The combined organic phase was dried over Na2SO4, filtered and the solvent was removed by distillation. Workup was carried out by means of column chromatography to give 1,3-dibenzyl-1,4,8-triazaspiro[4,5]decan-2-one in a yield of 7.8 g (75% of theory).

Provenance & Evidence