Hydrochloric Acid → HCID 19610852, compound

HRID 1602209Notes

Reaction equation

HRID 1602209 reaction equation
[O:1]=[C:2]1[C:18]2[C:17]([N+]([O-])=O)=[CH:16][CH:15]=[CH:14][C:13]=2[C:5]2[N:6]=[C:7]3[CH:12]=[CH:11][CH:10]=[CH:9][N:8]3[C:4]=2[C:3]1=[O:22].O.NN.N([O-])=O.[Na+].[ClH:30]>C(O)C.ClCCl.[Pd].O>[Cl:30][C:17]1[C:18]2[C:2](=[O:1])[C:3](=[O:22])[C:4]3[N:8]4[CH:9]=[CH:10][CH:11]=[CH:12][C:7]4=[N:6][C:5]=3[C:13]=2[CH:14]=[CH:15][CH:16]=1

Participants

9

Reactant 4

HCID 313Hydrochloric AcidHCID 24654Hydrazine hydrate (1:1)2×HCID 19610862HCID 19610862, compoundHCID 23668193Sodium Nitrite

Product 1

HCID 19610852HCID 19610852, compoundYield 14%

Reagents, catalysts & solvents 4

HCID 23938PalladiumCatalystHCID 702EthanolSolventHCID 962WaterSolventHCID 6344DichloromethaneSolvent

Conditions

Temperature
-10 °C

Procedure

A catalytic quantity of palladium on 10% carbon is added to an orange suspension of 80 mg (0.27 mmol, 1 eq) of 5,6-dihydro-5,6-dioxo-4-nitro-naphtho[1',2':4,5]imidazo-[1,2-a]pyridine in ethanol under argon, and the mixture is brought to reflux. 26.4 μL of hydrazine monohydrate (0.27 mmol, 1 eq) are then added. The reaction mixture immediately becomes violet. After 30 min, 26.4 μL of hydrazine monohydrate (0.27 mmol, 1 eq) are added. After 1 h of reaction, the reaction mixture is allowed to return to ambient temperature and the brown-violet precipitate is filtered through dried cotton and solubilized in 5 mL of conc. hydrochloric acid. This solution is cooled to -10° C., then a solution consisting of 34 mg (0.49 mmol, 1.8 eq) of sodium nitrite and 5 mL of distilled water is added dropwise. The medium is left under agitation at this temperature for 0.5 h. The reaction medium is added dropwise to a solution cooled to -5° C., consisting of 18 mg (0.18 mmol, 0.7 eq) of copper chloride(I) and 5 mL of conc. hydrochloric acid. The agitation is continued for 2.5 h. The reaction mixture is then diluted in dichloromethane, washed successively with a saturated solution of sodium carbonate, then with distilled water. The organic phase is extracted, then dried on sodium sulfate and evaporated to dryness. The raw product is purified on preparation plates (support: silica, eluent: dichloromethane/methanol, 90/10) to produce 10 mg of 4-chloro-5,6-dihydro-5,6-dioxo-naphtho[1',2':4,5]imidazo[1,2-a]pyridine in the form of yellow crystals.

Workup

  1. temperatureto reflux
  2. customAfter 1 h of reaction
  3. customto return to ambient temperature
  4. filtrationthe brown-violet precipitate is filtered
  5. customthrough dried cotton
  6. additionis added dropwise
  7. waitThe medium is left under agitation at this temperature for 0.5 h
  8. additionThe reaction medium is added dropwise to a solution
  9. temperaturecooled to -5° C.
  10. waitThe agitation is continued for 2.5 h
  11. washwashed successively with a saturated solution of sodium carbonate
  12. extractionThe organic phase is extracted
  13. customdried on sodium sulfate
  14. customevaporated to dryness
  15. customThe raw product is purified on preparation plates (support: silica, eluent: dichloromethane/methanol, 90/10)

Sources & evidence

ORD record
ord-fffe3cf9a6ef4fe6bd1511ca3ac2a077
Source dataset
uspto-grants-1999_11
Patent number
US05981544

Reaction notes

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