Reaction Steps
To a solution of 17-tetrabenzo(a,c,g,i)fluorenylmethyl-p-nitrophenyl carbonate (39.2 mg, 0.07 mmol) and glycine tert-butyl ester acetate salt (14.7 mg, 0.077 mmol; 1.1 equiv.) in dichloromethane (1.5 ml) was added N,N′-dimethyl aniline (18 μl, 0.14 mmol; 2 equiv). The reaction mixture was stirred at room temperature, under nitrogen, for 72 h. After addition of water (10 ml) and acidification with KHSO4 (2M; pH=1), the reaction mixture was extracted with dichloromethane (3×15 ml), washed with water (3×20 ml) and dried over MgSO4. The solvent was removed in vacuo to give an orange oil which was triturated in ether. A yellow solid was obtained which was filtered, washed with petrol (b.p. 40-60° C.) and dried to give compound (42) (30.6 mg, 79%); m.p. 170-171° C.; (Found: C, 79.7; H, 5.51; N, 2.33; C37H31NO4 requires: C, 80.3; H, 5.60; N, 2.53%); t.l.c. Rf (H) 0.79, Rf (I) 0.95; νmax (CH2Cl2) 3440 (secondary amide NH), 3060 (CH stretching, aromatic), 2940 (CH stretching, alkyl), 175 (CO, urethane, ester and slide I), 1600, 1500 (aromatic rings), 1520 (amide II), 1340 (OH bonding) cm−1, 1220, 1160, 1110 (CO stretching), 865, 850 (out of plane CH bonding); λmax 384 (16323), 367 (17656), 302 (42641), 290 (34313), 262 (62296) nm; δH (CDCl3, 80 MHz) 8.85-8.60 (6H, m, aromatic), 8.39-8.28 (2H, m, aromatic), 7.81-7.56 (8H, m, aromatic), 5.27 (1H, t, 3J=6 Hz, CH), 4.98 (1H, s broad, NH), 4.61 (2H, d, 3J=6 Hz, CH2), 3.74 (2H, d, 3J=6 Hz, CH2 glycine), 1.44 (9H, s, CH3×3); δc (CDCl3, 50 MHz) 168.7 (CO, ester), 156.1 (CO, urethane), 141.9, 136.7, 131.5, 130.3, 128.7, 127.9 (quaternary aromatic C's), 127.4, 126.8, 126.0, 125.8, 125.3, 124.9, 123.5, 123.1 (aromatic CH's), 82.0 (quaternary C, CMe3), 69.0 (CH2), 47.5 (CH), 43.2 (CH2, glycine), 27.9 (CH3×3); m/z (FAB) 553, 379. HRMS 553.22527, C37H31NO4 requires 553.22529 ( ) <1 ppm.
