Acetic Acid → Maribavir Impurity 57

HRID 1900118Notes

Reaction equation

HRID 1900118 reaction equation
[Br:1][C:2]1[N:6]([C@@H:7]2[O:19][C@H:18]([CH2:20][O:21][C:22](=[O:24])[CH3:23])[C@@H:13]([O:14]C(=O)C)[C@H:8]2[O:9]C(=O)C)[C:5]2[CH:25]=[C:26]([Cl:30])[C:27]([Cl:29])=[CH:28][C:4]=2[N:3]=1.CC([O-])=O.[K+].CC(O)=O>CO.O>[C:22]([O:21][CH2:20][C@H:18]1[O:19][C@@H:7]([N:6]2[C:5]3[CH:25]=[C:26]([Cl:30])[C:27]([Cl:29])=[CH:28][C:4]=3[N:3]=[C:2]2[Br:1])[C@H:8]([OH:9])[C@@H:13]1[OH:14])(=[O:24])[CH3:23]

Participants

5

Reactant 3

HCID 176Acetic AcidHCID 466020[(2R,3R,4R,5R)-3,4-diacetoxy-5-(2-bromo-5,6-dichloro-benzimidazol-1-yl)tetrahydrofuran-2-yl]methyl acetateHCID 517044Potassium Acetate

Product 1

HCID 22876558Maribavir Impurity 57

Reagents, catalysts & solvents 1

HCID 22242641Methanol--water (1/1)Solvent

Procedure

A mixture of 52a (1.048 g, 2.0 mmol) and KOAc (0.98 g, 10.0 mmol) in MeOH/H2O (40 mL/4 mL) was stirred at room temperature for 24 hr. AcOH (0.572 mL, 10.0 mmol) was added and stirring was continued at room temperature for 15 min. The reaction mixture was evaporated and the residue was partitioned between EtOAc/H2O (75 mL/75 mL). The EtOAc layer was washed with sat. NaCl solution (75 mL), dried (Na2SO4), and evaporated. The residue was chromatographed on a silica column (1.9×24 cm, eluted with CHCl3, 2%, 3%, 4% MeOH/CHCl3). Evaporation of fractions 15-27 (15 mL per fraction) and recrystallization from MeOH gave 0.50 g (2 crops, 57%) of 52b as white crystals. MP: 85°-95° C. (melted slowly over a large range) MS: (EI) m/e 437.9398 (15%, M+ =437.9385). 1H NMR (DMSO-d6): d 8.00, 7.95 (2×s, 2, 7-H and 4-H), 5.90 (d, 1, 1'-H, J1'-2' =7.5 Hz), 5.58 (d, 1, 2'-OH, J2'-2'OH =6.5 Hz), 5.46 (d, 1, 3'-OH, J3'-3'OH =4.5 Hz), 4.44 (dd, 1, 5'H, J5'-4' =4.5 Hz, J5'-5" =12.5 Hz), 4.43 (m, 1, 2'-H, J2'-3' =6.0 Hz), 4.24 (dd, 1, 5"-H, J5"-4' =2.0 Hz), 4.16 (m, 1, 4'-H, J3'-4' =3.0 Hz), 4.11 (m, 1, 3'-H), 2.15 (s, 3, 5'-OAc). 13C NMR (DMSO-d6): d 169.96 (COCH3), 142.57 (C3a), 132.49, 132.42 (C2 and C7a), 125.78, 125.74 (C5 and C6), 120.14 (C4), 113.28 (C7), 90.32 (C1'), 82.56 (C4'), 71.27 (C2'), 68.90 (C3'), 63.34 (C5'), 20.58 (COCH3). Anal. Calcd. for C14H13BrCl2N2O5 : C, 38.21; N, 6.37. Found: C, 38.37; H, 2.86; N, 6.27.

Workup

  1. stirringstirring
  2. waitwas continued at room temperature for 15 min
  3. customThe reaction mixture was evaporated
  4. customthe residue was partitioned between EtOAc/H2O (75 mL/75 mL)
  5. washThe EtOAc layer was washed with sat. NaCl solution (75 mL)
  6. dry with materialdried (Na2SO4)
  7. customevaporated
  8. customThe residue was chromatographed on a silica column (1.9×24 cm, eluted with CHCl3, 2%, 3%, 4% MeOH/CHCl3)
  9. customEvaporation of fractions 15-27 (15 mL per fraction) and recrystallization from MeOH

Sources & evidence

ORD record
ord-d7a7f81e8f7d4012ad64c258e33ec317
Source dataset
uspto-grants-1996_11
Patent number
US05574058

Reaction notes

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