TFA DCM MeOH → tert-Butyl 3-((2S)-amino-2-methoxycarbonylethyl)-2,4-dioxo-1,3,8-triazaspiro[4.5]decane-carboxylate

Participants

Reaction Steps

A solution of 4.6 g (7.5 mmol) of (34.4) in 180 ml of dichloromethane/methanol/trifluoroacetic acid=95.5/3/1.5 is stirred at room temperature for 10 min. The reaction mixture is concentrated and the residue is chromatographed through silica gel. 3.14 g (87%) of (34.5) are obtained after concentrating the product fractions.

Provenance & Evidence