tert-butyl N-(methylcarbamothioyl)carbamate → [(S)-4-(2-fluoro-5-nitro-phenyl)-1,4,5,5-tetramethyl-6-oxo-1,4,5,6-tetrahydro-pyrimidin-2-yl]-carbamic acid tert-butyl ester

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Starting from (S)-3-amino-3-(2-fluoro-5-nitro-phenyl)-2,2-dimethyl-butyric acid methyl ester and tert-butyl [(methylamino)carbonothioyl]carbamate (1.8 mmole), the product [(S)-4-(2-fluoro-5-nitro-phenyl)-1,4,5,5-tetramethyl-6-oxo-1,4,5,6-tetrahydro-pyrimidin-2-yl]-carbamic acid tert-butyl ester (31 mg) was obtained as pale yellow oil. MS (ESI): m/z=407.3 [M−H]−. A second fraction contained [(R)-4-(2-methoxy-5-nitro-phenyl)-1,4,5,5-tetramethyl-6-oxo-1,4,5,6-tetrahydro-pyrimidin-2-yl]-carbamic acid tert-butyl ester (270 mg) as a white solid. MS (ESI): m/z=419.3 [ M−H]−.

Provenance & Evidence