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

HRID 1825633Notes

Reaction equation

HRID 1825633 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-b6f396305843440bba3ee8e003917c4a
Source dataset
uspto-grants-2006_05
Patent number
US07045514B2

Reaction notes

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