Acetic Anhydride → HCID 10360434, compound

HRID 1736698Notes

Reaction equation

HRID 1736698 reaction equation
[CH:1]1([C:4]2[N:8]=[C:7]([C:9]3[N:10]=[CH:11][N:12]4[C:21]5[C:16](=[CH:17][CH:18]=[CH:19][CH:20]=5)[NH:15][C:14]([CH3:23])([CH3:22])[C:13]=34)[O:6][N:5]=2)[CH2:3][CH2:2]1.[C:24](OC(=O)C)(=[O:26])[CH3:25]>>[C:24]([N:15]1[C:16]2[C:21](=[CH:20][CH:19]=[CH:18][CH:17]=2)[N:12]2[CH:11]=[N:10][C:9]([C:7]3[O:6][N:5]=[C:4]([CH:1]4[CH2:3][CH2:2]4)[N:8]=3)=[C:13]2[C:14]1([CH3:23])[CH3:22])(=[O:26])[CH3:25]

Participants

3

Reactant 2

HCID 7918Acetic AnhydrideHCID 54315840HCID 54315840, compound

Product 1

HCID 10360434HCID 10360434, compound

Procedure

A mixture of 3-(3-cyclopropyl-1,2,4-oxadiazol-5-yl)-4,5-dihydro-4,4-dimethylimidazo-[1,5-a]quinoxaline (XXXIII, EXAMPLE 99, 0.19 g) and acetic anhydride (3 ml) is stirred at 100° for 3 days. Excess acetic anhydride is then removed under reduced pressure and the residue is partitioned between dichloromethane and aqueous sodium bicarbonate. The phases are separated and the organic phase is filtered through sodium sulfate and concentrated. The crude product is chromatographed on silica gel (200 ml) eluting with ethyl acetate/dichloromethane (20/80). The appropriate fractions are pooled and concentrated to give the title compound, mp 169°-171°; MS (m/z) at 349; IR (mineral oil) 1666, 1613, 1327, 1281 and 1504 cm-1 ; NMR (CDCl3) 1.12, 1.94, 2.16, 2.18, 7.20, 7.33, 7.52 and 8.14 δ.

Workup

  1. customExcess acetic anhydride is then removed under reduced pressure
  2. customthe residue is partitioned between dichloromethane and aqueous sodium bicarbonate
  3. customThe phases are separated
  4. filtrationthe organic phase is filtered through sodium sulfate
  5. concentrationconcentrated
  6. customThe crude product is chromatographed on silica gel (200 ml)
  7. washeluting with ethyl acetate/dichloromethane (20/80)
  8. concentrationconcentrated

Sources & evidence

ORD record
ord-3d54bb3ec77c45b684056eb22866e1fd
Source dataset
uspto-grants-1996_07
Patent number
US05541324

Reaction notes

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