Water → 10-hydroxymethylene-5H,10H-imidazo[1,2-a]indeno[1,2-e]pyrazin-4-one

HRID 2393386Notes

Reaction equation

HRID 2393386 reaction equation
CN([CH:4]=[C: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)C.O.C(=O)([O-])[OH:24].[Na+]>Cl.CS(C)=O>[OH:24][CH:4]=[C: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

6

Reactant 3

HCID 962Water2×HCID 516892Sodium BicarbonateHCID 5714456510-dimethylaminomethylene-5H,10H-imidazo[1,2-a]indeno[1,2-e]pyrazin-4-one

Product 1

HCID 5702351210-hydroxymethylene-5H,10H-imidazo[1,2-a]indeno[1,2-e]pyrazin-4-one

Reagents, catalysts & solvents 2

HCID 313Hydrochloric AcidSolventHCID 679Dimethyl SulfoxideSolvent

Procedure

10-Hydroxymethylene-5H,10H-imidazo[1,2-a]-indeno[1,2-e]pyrazin-4-one may be obtained in the following way: a solution of 1.4 g of 10-dimethylaminomethylene-5H,10H-imidazo[1,2-a]indeno-[1,2-e]pyrazin-4-one in 35 ml of 5N hydrochloric acid is stirred for 30 minutes at a temperature in the region of 25° C. After addition of 60 ml of water and neutralization with 120 ml of saturated aqueous sodium hydrogen carbonate, the solid formed is isolated by filtration, washed twice with 60 ml in total of water and air-dried. The product obtained (1.1 g) is dissolved in 120 ml of dimethyl sulphoxide and, after addition of 120 ml of water, the solid formed is isolated by filtration, washed twice with 10 ml in total of distilled water and twice with 10 ml in total of acetone and then dried under reduced pressure (1 mmHg; 0.13 kPa) at 100° C. 1 g of 10-hydroxymethylene-5H,10H-imidazo[1,2-a]indeno[1,2-e]pyrazin-4-one is thus obtained as a 60/40 mixture of the Z and E forms, decomposing without melting at 290° C. [NMR spectrum: (200 MHz; DMSO-d6 ; δ in ppm): a 60/40 mixture of isomers is observed: from 7.20 to 7.40 (mt, 2H: --H7 and --H8); 7.56 and 7.64-8.29 and 8.79 (4 broad s, twice 1H: --H of the imidazole); from 7.80 to 8.15 (mt, 2H: --H6 and --H9); 8.21 and 8.24 (2s, 1H in total: =CH--O--); 12.43 (mult., 1H: --NH--)].

Workup

  1. customthe solid formed
  2. customis isolated by filtration
  3. washwashed twice with 60 ml in total of water
  4. customair-dried
  5. customThe product obtained (1.1 g)
  6. customthe solid formed
  7. customis isolated by filtration
  8. washwashed twice with 10 ml in total of distilled water and twice with 10 ml in total of acetone
  9. customdried under reduced pressure (1 mmHg; 0.13 kPa) at 100° C

Sources & evidence

ORD record
ord-3303537faa814f2999dbb82eb90b12b4
Source dataset
uspto-grants-1998_09
Patent number
US05807859

Reaction notes

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