Hydrochloric Acid → 10-amino-5H,10H-imidazo[1,2-a]indeno[1,2-e]pyrazin-4-one hydrochloride

HRID 1290741Notes

Reaction equation

HRID 1290741 reaction equation
C([NH:4][CH:5]1[C:17]2[N:16]3[CH:18]=[CH:19][N:20]=[C:15]3[C:14](=[O:21])[NH:13][C:12]=2[C:11]2[CH:10]=[CH:9][CH:8]=[CH:7][C:6]1=2)(=O)C.[ClH:22]>O.CO>[ClH:22].[NH2:4][CH:5]1[C:17]2[N:16]3[CH:18]=[CH:19][N:20]=[C:15]3[C:14](=[O:21])[NH:13][C:12]=2[C:11]2[CH:10]=[CH:9][CH:8]=[CH:7][C:6]1=2

Participants

5

Conditions

Temperature
20 °C

Procedure

A solution of 12.9 g of 10-acetamido-5H,10H-imidazo[1,2-a]indeno[1,2-e]pyrazin-4-one in 650 ml of 2N aqueous hydrochloric acid solution is heated to boiling for 2 hours, cooled and then concentrated to dryness under reduced pressure (15 mmHg; 2 kPa) at 80° C. 4 g (of the 14.8 g obtained in total) are dissolved in 250 ml of distilled water and the solution is stirred for 16 hours at a temperature in the region of 20° C. The crystals formed are separated out by filtration, washed successively with 25 ml of distilled water and 25 ml of methanol and then air-dried at a temperature in the region of 20° C. The product obtained (3.5 g) is stirred in suspension for 10 minutes in 100 ml of boiling methanol and, after cooling and storing for 1 hour at 5° C., is isolated by filtration, washed with 20 ml of chilled methanol and then dried under reduced pressure (1 mmHg; 0.13 kPa) at 100° C. 2.1 g of 10-amino-5H,10H-imidazo[1,2-a]indeno[1,2-e]-pyrazin-4-one hydrochloride are thus obtained, decomposing without melting at about 240° C. [N.M.R. spectrum: (200 MHz; DMSO d6 ; δ in ppm): 5.70 (broad s, 1H: CH--N+ --Cl-); 7.48 and 7.58 (2t, J=7.5 Hz, 1H each: --H7 and --H8); 7.72 and 8.76 (2s, 1H each: --H of the imidazole); 7.98 and 8.09 (2d, J=7.5 Hz, 1H each: --H6 and --H9); 9.47 (cplx, 3H: N+ H3Cl-); 12.80 (cplx, 1H: --NH--)].

Workup

  1. temperaturecooled
  2. concentrationconcentrated to dryness under reduced pressure (15 mmHg; 2 kPa) at 80° C
  3. custom4 g (of the 14.8 g obtained in total)
  4. customThe crystals formed
  5. customare separated out by filtration
  6. washwashed successively with 25 ml of distilled water and 25 ml of methanol
  7. customair-dried at a temperature in the region of 20° C
  8. customThe product obtained (3.5 g)
  9. temperatureafter cooling
  10. waitstoring for 1 hour at 5° C.
  11. customis isolated by filtration
  12. washwashed with 20 ml of chilled methanol
  13. customdried under reduced pressure (1 mmHg; 0.13 kPa) at 100° C

Sources & evidence

ORD record
ord-da8f2a3778a8486196bd18a36677366c
Source dataset
uspto-grants-1998_05
Patent number
US05753657

Reaction notes

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