Hydrochloric Acid → 6-Methoxy-8-(4-Methyl-piperazin-1-yl)-4-oxo-4H-chromene-2-carboxylic acid hydrochloride

HRID 2414484Notes

Reaction equation

HRID 2414484 reaction equation
C([O:3][C:4]([C:6]1[O:7][C:8]2[C:13]([C:14](=[O:16])[CH:15]=1)=[CH:12][C:11]([O:17][CH3:18])=[CH:10][C:9]=2[N:19]1[CH2:24][CH2:23][N:22]([CH3:25])[CH2:21][CH2:20]1)=[O:5])C.CO.[ClH:28]>>[ClH:28].[CH3:18][O:17][C:11]1[CH:12]=[C:13]2[C:8](=[C:9]([N:19]3[CH2:24][CH2:23][N:22]([CH3:25])[CH2:21][CH2:20]3)[CH:10]=1)[O:7][C:6]([C:4]([OH:5])=[O:3])=[CH:15][C:14]2=[O:16]

Participants

4

Procedure

Ethyl-6-methoxy-8-(4-Methyl-piperazin-1-yl)-4-oxo-4H-chromene-2-carboxylate (1.0 g, 2.89 mmol), as prepared in Reference Example 2d above, was suspended in 6 M HCl (60 ml) and methanol (10 mL) and warmed to reflux for 3.0 h. The reaction was allowed to cool. The solution was concentrated in vacuo and anhydrous toluene was added (×3) and the solution was again concentrated in vacuo. The residue was dried under vacuum (17 h) to yield 6-methoxy-8-(4-methyl-1-piperazinyl)-4-oxo-4H-chromene-2-carboxylic acid hydrochloride as a yellow powder (1.0 g, quantitative yield).

Workup

  1. temperatureto reflux for 3.0 h
  2. temperatureto cool
  3. concentrationThe solution was concentrated in vacuo and anhydrous toluene
  4. additionwas added (×3)
  5. concentrationthe solution was again concentrated in vacuo
  6. customThe residue was dried under vacuum (17 h)

Sources & evidence

ORD record
ord-0328bfc1e2ff491fae68829496a62142
Source dataset
uspto-grants-2004_11
Patent number
US06812225B2

Reaction notes

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