Regioselective nitration of N(alpha),N(1)-bis(trifluoroacetyl)-L-tryptophan methyl ester: efficient synthesis of 2-nitro and 6-nitro-N-trifluoroacetyl-L-tryptophan methyl ester.
Nitration of N(alpha),N(1)-bis(trifluoroacetyl)-l-tryptophan methyl ester with HNO(3) in acetic anhydride at 0 degrees C provides N(alpha)-trifluoroacetyl-2-nitro-l-tryptophan methyl ester in 67% yield, whereas nitration in trifluoroacetic acid at 0 degrees C gives N(alpha)-trifluoroacetyl-6-nitro-l-tryptophan methyl ester in 69% yield.
Department of Chemistry, University of Georgia, Athens, GA 30602, USA.
Andrew S
AS
Osborne
Phanneth
P
Som
Jessica L
JL
Metcalf
Robert S
RS
Phillips
D002851:Chromatography, High Pressure Liquid; D009682:Magnetic Resonance Spectroscopy; D009566:Nitrates / Q000737:chemistry*; D014364:Tryptophan / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry
D009566:Nitrates; C028129:tryptophan methyl ester; D014364:Tryptophan