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

HRID 2393362Notes

Reaction equation

HRID 2393362 reaction equation
[NH2:1][CH:2]1[C:14]2[N:13]3[CH:15]=[CH:16][N:17]=[C:12]3[C:11](=[O:18])[NH:10][C:9]=2[C:8]2[CH:7]=[CH:6][CH:5]=[CH:4][C:3]1=2.C(NC1C2N3C=CN=C3C(=O)NC=2C2C=CC=CC1=2)(=O)C.[ClH:40]>O.CO>[ClH:40].[NH2:1][CH:2]1[C:14]2[N:13]3[CH:15]=[CH:16][N:17]=[C:12]3[C:11](=[O:18])[NH:10][C:9]=2[C:8]2[CH:7]=[CH:6][CH:5]=[CH:4][C:3]1=2

Participants

6

Reactant 3

HCID 313Hydrochloric AcidHCID 1529136110-acetamido-5H,10H-imidazo[1,2-a]indeno[1,2-e]pyrazin-4-oneHCID 1529136210-Amino-5H,10H-imidazo[1,2-a]indeno-[1,2-e]pyrazin-4-one

Product 1

HCID 1897547210-amino-5H,10H-imidazo[1,2-a]indeno[1,2-e]pyrazin-4-one hydrochloride

Reagents, catalysts & solvents 2

HCID 887MethanolSolventHCID 962WaterSolvent

Conditions

Temperature
20 °C

Procedure

10-Amino-5H,10H-imidazo[1,2-a]indeno-[1,2-e]pyrazin-4-one may be prepared in the following way: 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 aqueous 2N 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 (out 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 isolated 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. (NMR 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 (mult., 3H: N+H3Cl--); 12.80 (mult., 1H: --NH--)).

Workup

  1. temperaturecooled
  2. concentrationconcentrated to dryness under reduced pressure (15 mmHg; 2 kPa) at 80° C
  3. custom4 g (out of the 14.8 g obtained in total)
  4. customThe crystals formed
  5. customare isolated 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-ca3d377d363a4e39a1bfd877470cae0c
Source dataset
uspto-grants-1998_09
Patent number
US05807859

Reaction notes

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