(2S)-2-amino-N,N,3,3-tetramethylbutanamide

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of 7-methyl-1-[2-(methylthio)ethyl]-1,3-dihydro-2H-benzimidazol-2-one (0.21 g, 0.93 mmol) in 1,2-dichloroethane (5 mL) were added triethylamine (0.43 mL, 3.1 mmol) and 4-nitrophenyl chloroformate (0.23 g, 1.1 mmol) at 0° C. and the mixture was stirred at rt for 4 h. Then to this mixture was added a solution of N,N-dimethyl-tert-leucinamide (ca. 1.4 mmol, prepared according to the procedure described in steps 1 and 2 of example 3 from dimethylamine hydrochloride) in 1,2-dichloroethane (3 mL) at 0° C. and stirred rt. After 14 h, the reaction was quenched by addition of water (50 mL) and extracted with dichloromethane (50 mL×2). The combined organic layers were washed with water (30 mL×4), brine (30 mL), dried over sodium sulfate, filtered and concentrated in vacuo. The residue was purified by preparative TLC eluting with dichloromethane/methanol (10/1) to afford 0.31 g (83%) of the title compound. prepared at 0° C. stirred rt After 14 h the reaction was quenched by addition of water (50 mL) extracted with dichloromethane (50 mL×2) The combined organic layers were washed with water (30 mL×4), brine (30 mL) dried over sodium sulfate filtered concentrated in vacuo The residue was purified by preparative TLC eluting with dichloromethane/methanol (10/1)

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of 7-methyl-1-[2-(methylthio)ethyl]-1,3-dihydro-2H-benzimidazol-2-one (0.21 g, 0.93 mmol) in 1,2-dichloroethane (5 mL) were added triethylamine (0.43 mL, 3.1 mmol) and 4-nitrophenyl chloroformate (0.23 g, 1.1 mmol) at 0° C. and the mixture was stirred at rt for 4 h. Then to this mixture was added a solution of N,N-dimethyl-tert-leucinamide (ca. 1.4 mmol, prepared according to the procedure described in steps 1 and 2 of example 3 from dimethylamine hydrochloride) in 1,2-dichloroethane (3 mL) at 0° C. and stirred rt. After 14 h, the reaction was quenched by addition of water (50 mL) and extracted with dichloromethane (50 mL×2). The combined organic layers were washed with water (30 mL×4), brine (30 mL), dried over sodium sulfate, filtered and concentrated in vacuo. The residue was purified by preparative TLC eluting with dichloromethane/methanol (10/1) to afford 0.31 g (83%) of the title compound. prepared at 0° C. stirred rt After 14 h the reaction was quenched by addition of water (50 mL) extracted with dichloromethane (50 mL×2) The combined organic layers were washed with water (30 mL×4), brine (30 mL) dried over sodium sulfate filtered concentrated in vacuo The residue was purified by preparative TLC eluting with dichloromethane/methanol (10/1)