Methyl iodide → (2S,5S)-tert-butyl 2-(tert-butyl)-3,5-dimethyl-4-oxoimidazolidine-1-carboxylate

Participants

Reaction Steps

To a solution of (S)-tert-butyl 2-(tert-butyl)-3-methyl-4-oxoimidazolidine-1-carboxylate (0.5 g, 1.95 mmol; available from Aldrich#337595) in dry THF (15 ml) cooled to −78° C., LDA 2M in THF/heptane (0.97 ml, 1.95 mmol) was added and the reaction mixture stirred at this temperature for 40 min before adding iodomethane (0.146 ml, 2.34 mmol). The reaction was allowed to warm to RT and stirred for 18 hrs. The reaction mixture was cooled again at −78° C. then LDA 2M in THF/hepatane (0.3 ml) and iodomethane (0.04 ml, 0.6 mmol) were added in sequence. The mixture was allowed to reach RT and further stirred for 5 hrs. The resulting solution was treated with NH4Cl sat sol (5 ml) and extracted with Et2O. The organic phases were collected and washed with NaCl sat sol, dried over Na2SO4 and evaporated in vacuo to afford a residue which was purified by Biotage SNAP-Si column (25 g) eluting with cHex/Et2O 60/40. Collected fractions after solvent evaporation afforded the title compound (D43) (430 mg).

Provenance & Evidence