Ammonium Chloride → (2S,5R)-tert-butyl 2-(tert-butyl)-5-(4-chlorobutyl)-3,5-dimethyl-4-oxoimidazolidine-1-carboxylate

Participants

Reaction Steps

To a solution of (2S,5S)-tert-butyl 2-(tert-butyl)-3,5-dimethyl-4-oxoimidazolidine-1-carboxylate (D43) (430 mg, 1.59 mmol) in dry THF (15 ml) cooled to −78° C., LDA 2M in THF/heptane (1.2 ml, 2.38 mmol) was added and the reaction mixture stirred at this temperature for 40 min before adding 1-bromo-4-chloro-butane (0.27 ml, 2.38 mmol). The reaction was allowed to warm to RT and left stirring for 3 hrs. The resulting solution was treated with NH4Cl sat sol (5 ml) and extracted with Et2O (3×10 ml). 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 (D44) (465 mg).

Provenance & Evidence