Dimethyl Sulfate → HCID 11325332, compound

Participants

Reaction Conditions

Reaction Steps

A solution containing N-(5-aminothiophene-2-carbonyl)-L-glutamic acid diethyl ester (III-3 where R2 is H) (1.78 g, 5.42 mmol), (i-Pr)2NEt (1.0 mL, 0.74 g, 5.7 mmol), and Me2SO4 (0.59 mL, 0.79 g, 6.2 mmol) in 20 mL N,N-dimethylformamide (DMF) was warmed at 60° C. for 2 hours, then left at 20°-25° C. for 42 hours. The solution was evaporated in vacuo (1 mm, bath 25°-30° C.), and the residue was dissolved in EtOAc-cyclohexane (1:1 by volume) for application to a silica gel column. Elution by the same solvent system afforded fractions homogeneous by TLC of the product. Fractions were combined and evaporated to afford 16% yield (287 mg) of N-[5-(methylamino)thiophene-2-carbonyl]-L-glutamic acid diethyl ester (III-3) R2 =CH3 as an amber oil.

Provenance & Evidence