Acetic Anhydride → [9-Chloro-1-(2,4-dichlorophenyl)-1,2,3,4-tetrahydropyrimido[1,2-a]benzimidazol-6-yl](cyclopropyl)methyl acetate

HRID 1399152Notes

Reaction equation

HRID 1399152 reaction equation
[Cl:1][C:2]1[C:10]2[N:9]=[C:8]3[N:11]([C:15]4[CH:20]=[CH:19][C:18]([Cl:21])=[CH:17][C:16]=4[Cl:22])[CH2:12][CH2:13][CH2:14][N:7]3[C:6]=2[C:5]([CH:23]([CH:25]2[CH2:27][CH2:26]2)[OH:24])=[CH:4][CH:3]=1.[C:28](OC(=O)C)(=[O:30])[CH3:29]>N1C=CC=CC=1>[C:28]([O:24][CH:23]([C:5]1[C:6]2[N:7]3[CH2:14][CH2:13][CH2:12][N:11]([C:15]4[CH:20]=[CH:19][C:18]([Cl:21])=[CH:17][C:16]=4[Cl:22])[C:8]3=[N:9][C:10]=2[C:2]([Cl:1])=[CH:3][CH:4]=1)[CH:25]1[CH2:27][CH2:26]1)(=[O:30])[CH3:29]

Participants

4

Reactant 2

HCID 7918Acetic AnhydrideHCID 57786088[9-Chloro-1-(2,4-dichlorophenyl)-1,2,3,4-tetrahydropyrimido[1,2-a]benzimidazol-6-yl](cyclopropyl)methanol

Product 1

HCID 57786248[9-Chloro-1-(2,4-dichlorophenyl)-1,2,3,4-tetrahydropyrimido[1,2-a]benzimidazol-6-yl](cyclopropyl)methyl acetateYield 72%

Reagents, catalysts & solvents 1

HCID 1049PyridineSolvent

Procedure

To a solution of [9-chloro-1-(2,4-dichlorophenyl)-1,2,3,4-tetrahydropyrimido[1,2-a]benzimidazol-6-yl](cyclopropyl)methanol (120.0 mg, 0.284 mmol) in pyridine (0.5 mL) was added acetic anhydride (0.3 mL) at 0° C. The reaction mixture was stirred at room temperature for 7 hrs. The mixture was concentrated. The residue was neutralized with aqueous saturated sodium hydrogen carbonate and extracted with ethyl acetate (×3). The combined organic layer was washed with brine (×1), dried over anhydrous magnesium sulfate, filtered and concentrated in vacuo. The residue was purified, by silica gel column chromatography eluting with a 0-40% ethyl acetate/n-hexane gradient mixture. The residue was recrystallized from diisopropyl ether/n-hexane to give the title compound as a colorless powder (94.5 mg, 0.203 mmol, 72%).

Workup

  1. concentrationThe mixture was concentrated
  2. extractionextracted with ethyl acetate (×3)
  3. washThe combined organic layer was washed with brine (×1)
  4. dry with materialdried over anhydrous magnesium sulfate
  5. filtrationfiltered
  6. concentrationconcentrated in vacuo
  7. customThe residue was purified, by silica gel column chromatography
  8. washeluting with a 0-40% ethyl acetate/n-hexane gradient mixture
  9. customThe residue was recrystallized from diisopropyl ether/n-hexane

Sources & evidence

ORD record
ord-27272a39ae9443b39c0d7bedf83ab685
Source dataset
uspto-grants-2014_12
Patent number
US08901141B2

Reaction notes

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