Acetic Anhydride → HCID 10360434, compound
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
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/dichlommethane (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
- customExcess acetic anhydride is then removed under reduced pressure
- customthe residue is partitioned between dichloromethane and aqueous sodium bicarbonate
- customThe phases are separated
- filtrationthe organic phase is filtered through sodium sulfate
- concentrationconcentrated
- customThe crude product is chromatographed on silica gel (200 ml)
- washeluting with ethyl acetate/dichlommethane (20/80)
- concentrationconcentrated
Sources & evidence
- ORD record
- ord-f0148ab2053b4279ad392eb926acb854
- Source dataset
- uspto-grants-1997_09
- Patent number
- US05668282
Reaction notes
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