Diisopropylethylamine → HCID 59236985, compound

Participants

Reaction Steps

To a solution of J4 (1.8 g, 4.86 mmol) in EtOAc (5 mL) was added HCl/Dioxane (10 mL of 4N), and the reaction was stirred 4 hr. The solvents were removed in vacuo, and the HCl salt was exposed to high vacuum for 18 h to give (S)-2-azido-1-(2-pyrrolidin-2-yl)-1H-benzo[d]imidazol-6-yl)ethanone 2HCl as a yellow solid. HATU (1.94 g, 5.10 mmol) was added to the HCl salt of (S)-2-azido-1-(2-(pyrrolidin-2-yl)-1H-benzo[d]imidazol-6-yl)ethanone (1.8 g, 4.86 mmol), (R)-2-(dimethylamino)-2-phenylacetic acid HCl salt (1.05 g, 4.86 mmol), and Hunig's base (3.4 mL, 19.4 mmol) in DMF (50 mL) while being rapidly stirred 6 h. The solvent was removed in vacuo and the reside was partitioned into two lots and separately pre-absorbed onto SiO2 (CH2Cl2), and subjected to flash chromatography on a 40 M Biotage silica gel column pre-equilibrated 2% B, and eluted with 2% B (150 mL); Segment 2: 2-40% B (1200 mL); Segment 3: 40-80% (600 mL). A=CH2Cl2; B=25% MeOH/CH2Cl2 to give J4.a (R)-1-((S)-2-(6-(2-azidoacetyl)-1H-benzo[d]imidazol-2-yl)pyrrolidin-1-yl)-2-(dimethylamino)-2-phenylethanone (combined lots: (1.05 g, 50%)) as a yellow foam. 1H NMR (500 MHz, DMSO-d6) δ: 8.16 (s, 1H), 7.82 (dd, J=8.8, 1.5 Hz, 1H), 7.65 (d, J=8.5 Hz, 1H), 7.60-7.56 (m, 5H), 5.51 (s, 1H), 5.22 (dd, J=8.2, 2.8, 1H), 4.95 (m, 2H), 4.09-4.05 (m, 1H), 3.17-3.12 (m, 1H), 2.90/2.84 (br. s, 6H), 2.23-2.19 (m, 1H), 2.21-1.89 (m, 3H). LC (D-Cond. 2): RT=1.53 min; LC/MS: Anal. Calcd. for [M+H]+ C23H26N7O2: 432.22. found: 431.93. HRMS Anal. Calcd. for [M+H]+ C23H26N7O2: 432.2148. found: 432.2127.

Provenance & Evidence