Guanidine Hydrochloride → Ethyl 8-amino-1-methyl-1H-pyrazolo[4,3-h]quinazoline-3-carboxylate

HRID 44593Notes

Reaction equation

HRID 44593 reaction equation
[CH2:1]([O:3][C:4]([C:6]1[C:14]2[CH2:13][CH2:12][C:11](=[CH:15]N(C)C)[C:10](=O)[C:9]=2[N:8]([CH3:20])[N:7]=1)=[O:5])[CH3:2].Cl.[NH2:22][C:23]([NH2:25])=[NH:24]>C(O)C.CC[O-].[Na+]>[NH2:24][C:23]1[N:25]=[CH:15][C:11]2[CH:12]=[CH:13][C:14]3[C:6]([C:4]([O:3][CH2:1][CH3:2])=[O:5])=[N:7][N:8]([CH3:20])[C:9]=3[C:10]=2[N:22]=1

Participants

5

Reactant 2

HCID 5742Guanidine HydrochlorideHCID 67075650ethyl 6-[(dimethylamino)methylene]-1-methyl-7-oxo-4,5,6,7-tetrahydro-1H-indazole-3-carboxylate

Product 1

HCID 57444093Ethyl 8-amino-1-methyl-1H-pyrazolo[4,3-h]quinazoline-3-carboxylateYield 85%

Reagents, catalysts & solvents 2

HCID 702EthanolSolventHCID 2723922Sodium ethoxideSolvent

Procedure

16.00 g (0.06 mol) of ethyl-6-[(dimethylamino)methylene]-1-methyl-7-oxo-4,5,6,7-tetrahydro-1H-indazole-3-carboxylate were dissolved in 600 mL of ethanol and 3.90 g of sodium ethylate, and 5.44 g of guanidine hydrochloride were added consecutively. The solution was stirred at reflux for 12 hours. The solvent was then evaporated, the residue redissolved with dichloromethane and washed with water. The organic layer was then dried over anhydrous Na2SO4 and concentrated. The residue was triturated with diethyl ether and the product collected by filtration (85% yield as a white solid).

Workup

  1. temperatureat reflux for 12 hours
  2. customThe solvent was then evaporated
  3. dissolutionthe residue redissolved with dichloromethane
  4. washwashed with water
  5. dry with materialThe organic layer was then dried over anhydrous Na2SO4
  6. concentrationconcentrated
  7. customThe residue was triturated with diethyl ether
  8. filtrationthe product collected by filtration (85% yield as a white solid)

Sources & evidence

ORD record
ord-4469cbe0f5874bb0a1dfebaf757e02f6
Source dataset
uspto-grants-2013_09
Patent number
US08541429B2

Reaction notes

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