Reaction Steps
To a round-bottomed flask containing the salt (propargyl)Co2(CO)6+BF4− (0.390 g, 0.95 mmol) under argon was added anhydrous dichloromethane (dried by distillation over P2O5; 14 ml), a nearly clear solution was obtained. To this solution a suspension of tert-butyl 4-{N-[(6RS)-2-hydroxymethyl-4-oxo-3,4,7,8-tetrahydro-6H-cyclopenta[g]quinazolin-6-yl]amino}benzoate (0.285 g, 0.71 mmol) in anhydrous CH2Cl2 (14 ml) and DME (distilled over CaH2, 20 ml) was added in one portion. The mixture was stirred at room temperature for 10 min under argon, then diisopropylethylamine (0.14 ml) was added and stirring was continued at room temperature for 20 min. The reaction mixture was then partitioned between AcOEt (350 ml) and brine (100 ml). The organic layer was washed with 10% aqueous citric acid (100 ml), and brine (100 ml), dried (Na2SO4), and concentrated in vacuo. Purification by chromatography (FlashMaster personal system by Jones Chromatography, isolute 20 g-70 ml column), on elution with 70% AcOEt in CH2Cl2, gave a red solid (0.391 g, 76%), mp 190° C. (dec); 1H-NMR (250 MHz, DMSO-d6, TMS) 1.52 (s, 9H, C(CH3)3), 2.24, 2.60 (2×m, 1H each, 7-CH), 2.96-3.25 (m, 2H, 8-CH2), 4.37 (d, J=5.90 Hz, 2H 2-CH2OH), 4.65 (ABq, J=17.2 Hz, 2H, N10—CH2), 5.55 (t, J=6.2 Hz, 1H, CH2OH), 5.80 (t, J=7.7 Hz, 1H, 6-CH), 6.68 (s, 1H, propargyl H), 7.01 (d, J=8.8 Hz, 2H, 3′,5′-ArH), 7.56, 7.76 (2×s, 1H each, 5-H and 9-H), 7.79 (d, J=9.8 Hz, 2H, 2′,6′-ArH), 11.83 (s, 1H, CONH). To a solution of this material (0.380 g, 0.52 mmol) in EtOH (65 ml) was added Fe(NO3)3 9H2O (2.60 g, 6.5 mmol). The mixture was stirred at room temperature for 2.5 h, brine (˜200 ml) was then added into the reaction mixture that was then extracted with AcOEt (3×150 ml). The combined organic extracts were washed with brine (120 ml), dried (Na2SO4), and concentrated in vacuo. Purification by column chromatography, on elution with 5% MeOH in AcOEt , gave an off-white solid (0.161 g, 705), mp 195-197° C.; 1H-NMR (250 MHz, DMSO-d6, TMS) 1.52 (s, 9H, C(CH3)3), 2.17 (m), 2.55 (m obscured by the DMSO peak) (1H each, 7-CH), 2.90-3.20 (m, 3H, C≡CH, 8-CH2), 3.98 (ABq, J=18.7 Hz, 2H, N10—CH2), 4.38 (d, J=5.8 Hz, 2H 2-CH2OH), 5.56 (t, poorly resolved, 1H, CH2OH), 5.78 (t, J=8.7 Hz, 1H, 6-CH), 7.02 (d, J=9.0 Hz, 2H, 3′,5′-ArH), 7.55, 7.80 (2×s, 1H each, 5H and 9-H), 7.76 (d, J=9.8 Hz, 2H, 2′,6′-ArH), 11.82 (s, 1H, CONH); MS (ESI, m/z) 468 [(M+Na)+, 60%], 446 [(M+H)+, 50%], 390 [(M-tBu)+, 70%], 215 (100%); Found: C, 69.63; H, 6.13; N, 9.31; C26H27N3O4 requires C, 70.09; H, 6.11; N, 9.43%. FAB-HRMS, measured: 445.2017, calculated for C26H27N3O4 (M+): 445.2002.
