11% |
Stage #1: Langlois reagent; α-glu-trp With tert.-butylhydroperoxide; iron(III) chloride; ammonium formate In water; dimethyl sulfoxide at 40℃; for 0.5h;
Stage #2: trifluoroacetic acid In water; dimethyl sulfoxide; acetonitrile |
GluTrp[W-2-CF3J (S)-4-carboxy-l-(((S)-l-carboxy-2-(2-(trifluoromethyl)-lH-indol-3-yl)ethyl)amino)-l- oxobutan-2-aminium trifluoroacetate
To GluTrp (10.4 mg, 31 pmol) in a 3 mL screw top V-Vials with open-top cap (Sigma- Aldrich Z115142) was added 90 pL ofDMSO, Iron (III) Chloride (5.5 mg, 34 pmol), NaS02CF3 (45 pmol, 45 pL of a 1M stock solution in 25mM aqueous NH4HCO2), and 70% TBHP in water (84 pmol, 45 pL of a 1.87M stock solution in 25mM aqueous NH4HCO2). The vial was placed in a water bath at 40°C and stirred at 760 rpm for 30 mins. The crude reaction mixture was diluted with about 2 mL of 5% MeCN (aq) with 0.1% TFA and each time 0.5 mL was injected into the HPLC loop (1 mL) for purification. A white solid which slowly turns brown at -20°C was obtained after lyophilization (4.6mg, 3.4pmol, 11%). Reverse phase HPLC details: Phenomenex Synergi 4pm Hydro RP 80A, 250 x 10mm. Flow rate = 4 rnL/min. Column temperature = 40°C. Eluent = 12% MeCN (0.1% TFA) and 88% H2O (0.1% TFA) for 3 mins then increase linearly to 40% MeCN at 25 mins. Retention time = 17.7 mins. *H NMR (500 MHz, DMSO-i/e) d 12.90 (s, 1H), 12.05 (s, 1H), 8.94 (d, J = 8.0 Hz, 1H), 8.12 (d, J= 5.3 Hz, 3H), 7.76 (d, J= 8.1 Hz, 1H), 7.44 (d , J= 8.3 Hz, 1H), 7.29 (t, J= 7.6 Hz, 1H), 7.14 (t, J= 7.5 Hz, 1H), 4.54 (q, J= 7.6 Hz, 1H), 3.78 (q, J= 5.7 Hz, 1H), 3.34 (dd, J = 14.5, 7.9 Hz, 1H), 3.22 (dd, J= 14.8, 7.1 Hz, 1H), 2.38 - 2.31 (m, 2H), 1.98 (dt, J= 9.4, 6.7 Hz, 2H). 13C NMR (126 MHz, DMSC ,) d 173.38, 172.18, 168.29, 158.85 - 156.88 (m), 135.63, 126.73, 124.35, 122.15 (q, J= 268.7 Hz), 121.62 (q , J= 36.1 Hz), 120.12, 119.97, 116.73 (q, J= 297.1 Hz), 112.36, 112.15 (q, J= 2.7 Hz), 53.50, 51.45, 28.84, 26.33, 26.l5.19F NMR (471 MHz, DMSO-t/e) d -57.32, -74.95. HRMS (ESI+): for C17H19O5N3F3 [M+H]+ requires 402.1271 m/z found 402.1268 m/z. [a]25 = +14±2° (c 0.040 , H2O). Major Trifluoromethylated Side Products of Glu-Trp Reactions (S)-4-carboxy-l-(((S)-l-carboxy-2-(7-(trifluoromethyl)-lH-indol-3-yl)ethyl)amino)-l- oxobutan-2-aminium and (S)-4-carboxy-l-(((S)-l-carboxy-2-(4-(trifluoromethyl)-lH- indol-3-yl)ethyl)amino)-l-oxobutan-2-aminium (not separated) Reverse phase HPLC details: Phenomenex Synergi 4mhi Hydro RP 80A, 250 x lOmm. Flow rate = 4 Column temperature = 40°C. Eluent = 12% MeCN (0.1% TFA) and 88% H20 (0.1% TFA) for 3 mins then increase linearly to 40% MeCN at 25 mins. Retention time 21.4 mins. (4-CF3 and 7-CF3 are not separated). 4-CFs *H NMR (500 MHz, DMSO-i/e) d 12.33 (s, 1H), 11.64 - 11.51 (m, 1H), 8.87 (d, J= 7.7 Hz, 1H), 8.09 (s, 3H), 7.71 (d, J= 8.1 Hz, 1H), 7.43 (d , J= 7.3 Hz, 1H), 7.41 (d , J= 2.6 Hz, 2H), 7.24 (t, J= 7.8 Hz, 1H), 4.69 - 4.46 (m, 1H), 3.82 (s, 1H), 3.48 - 2.99 (m, 2H), 2.07 - 1.91 (m, 4H). 19F NMR (471 MHz, DMSO- e) d -57.66, -61.23, -74.95. Insufficient quantity for 13 C NMR. HRMS (ESI+): for C17H1905 3F3 [M+H]+ requires 402.1271 m/z found 402.1279 m/z. 7-CF3 *H NMR (500 MHz, DMSC ,) d 12.88 (s, 2H), 11.32 (d, .7= 2.1 Hz, 1H), 8.76 (d, J= 7.7 Hz, 1H), 8.09 (s, 3H), 7.87 (d, J= 7.9 Hz, 1H), 7.45 (d, J= 6.8 Hz, 1H), 7.32 (d, J= 2.1 Hz, 1H), 7.18 (t, J= 7.7 Hz, 1H), 4.69 - 4.46 (m, 1H), 3.82 (s, 1H), 3.36 - 2.99 (m, 2H), 2.07 - 1.91 (m, 4H). 19F NMR (471 MHz, DMSO- e) d -57.66, -61.23, -74.95. Insufficient quantity for 13CNMR. HRMS (ESI+): for C17H1905N3F3 [M+Hf requires 402.1271 m/z found 402.1279 m/z. |