Dimethyl Sulfoxide → HCID 11641110, compound

Participants

Reaction Conditions

Reaction Steps

Following the procedure described in J. Org. Chem. 1994, 59(7), 1771, to a solution of oxalyl chloride (0.17 mmol) in dichloromethane at −78° C. is added a solution of dimethylsulfoxide (0.348 mmol, 0.025 mL) in dichloromethane dropwise. After 10 min a solution of (2S)-N-[(1S,2E)-4-hydroxy-1-isopropyl-3-methyl-2-butenyl]-N,3,3-trimethyl-2-{[(2S)-3-methyl-2-(methylamino)-3-phenylbutanoyl]amino}butanamide trifluoroacetic acid (83 mg, from Example 81) in dichloromethane is added dropwise. After 20 min triethylamine (0.725 mmol, 0.1 mL) is added dropwise. The reaction mixture is allowed to warm to 25° C. then washed with water and dried over anhydrous sodium sulfate. Concentration in vacuo and purification by reverse phase HPLC (0.01% aqueous trifluoroacetic acid/acetonitrile gradient system) gave the trifluoracetic acid salt of N,β,β-trimethyl-L-phenylalanyl-N1-[(1S,2E)-1-isopropyl-3-methyl-4-oxo-2-butenyl]-N1,3-dimethyl-L-valinamide as a white powder (43 mg) MS (ES): m/z 458.1 (M+H) and 4-(dimethylsulfonio)-N,β,β-trimethyl-L-phenylalanyl-N1-[(1S,2E)-1-isopropyl-3-methyl-4-oxo-2-butenyl]-N1,3-dimethyl-L-valinamide trifluoroacetate as a clear glass (28 mg) MS (ES): m/z 518.0 (M+).

Provenance & Evidence