Acetic Anhydride → 1-[9-Chloro-1-(6-methoxy-4-methylpyridin-3-yl)-1,2,3,4-tetrahydropyrimido[1,2-a]benzimidazol-6-yl]propyl acetate

HRID 1628736Notes

Reaction equation

HRID 1628736 reaction equation
[C:1](OC(=O)C)(=[O:3])[CH3:2].[Cl:8][C:9]1[C:17]2[N:16]=[C:15]3[N:18]([C:22]4[CH:23]=[N:24][C:25]([O:29][CH3:30])=[CH:26][C:27]=4[CH3:28])[CH2:19][CH2:20][CH2:21][N:14]3[C:13]=2[C:12]([CH:31]([OH:34])[CH2:32][CH3:33])=[CH:11][CH:10]=1>N1C=CC=CC=1>[C:1]([O:34][CH:31]([C:12]1[C:13]2[N:14]3[CH2:21][CH2:20][CH2:19][N:18]([C:22]4[CH:23]=[N:24][C:25]([O:29][CH3:30])=[CH:26][C:27]=4[CH3:28])[C:15]3=[N:16][C:17]=2[C:9]([Cl:8])=[CH:10][CH:11]=1)[CH2:32][CH3:33])(=[O:3])[CH3:2]

Participants

4

Procedure

Acetic anhydride (103 μL, 1.09 mmol) was added to a stirred solution of 1-[9-chloro-1-(6-methoxy-4-methylpyridin-3-yl)-1,2,3,4-tetrahydropyrimido[1,2-a]benzimidazol-6-yl]propan-1-ol (140 mg, 0.362 mmol) in pyridine (1.2 mL) at room temperature, and the mixture was stirred at room temperature for 19 hr. The mixture was concentrated in vacuo, diluted with saturated aqueous sodium hydrogen carbonate, and extracted with ethyl acetate. The combined organic layer was washed with brine, dried over anhydrous magnesium sulfate, filtered and concentrated in vacuo. The residue was purified by flash column chromatography on silica gel eluting with a 10-50% ethyl acetate/n-hexane gradient mixture. The filtrate was concentrated in vacuo to give the title compound as a colorless amorphous (89.9 mg, 0.210 mmol, 58%).

Workup

  1. concentrationThe mixture was concentrated in vacuo
  2. additiondiluted with saturated aqueous sodium hydrogen carbonate
  3. extractionextracted with ethyl acetate
  4. washThe combined organic layer was washed with brine
  5. dry with materialdried over anhydrous magnesium sulfate
  6. filtrationfiltered
  7. concentrationconcentrated in vacuo
  8. customThe residue was purified by flash column chromatography on silica gel eluting with a 10-50% ethyl acetate/n-hexane gradient mixture
  9. concentrationThe filtrate was concentrated in vacuo

Sources & evidence

ORD record
ord-cf31acb422d540f5ba5327c0d05f9d34
Source dataset
uspto-grants-2014_07
Patent number
US08785460B2

Reaction notes

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