Hydrochloric Acid → HCID 22402101, compound

HRID 2254030Notes

Reaction equation

HRID 2254030 reaction equation
Cl.N([O-])=O.[Na+].[Cl:6][C:7]1[C:15]([N:16]=NC2C=CC(OC)=CC=2)=[C:10]2[CH:11]=[CH:12][CH:13]=[CH:14][N:9]2[N:8]=1.S(S([O-])=O)([O-])=O.[Na+].[Na+]>O>[ClH:6].[NH2:16][C:15]1[C:7]([Cl:6])=[N:8][N:9]2[CH:14]=[CH:13][CH:12]=[CH:11][C:10]=12

Participants

6

Reactant 4

HCID 313Hydrochloric Acid2×HCID 24489Sodium DithioniteHCID 22402088HCID 22402088, compoundHCID 23668193Sodium Nitrite

Product 1

HCID 22402101HCID 22402101, compound

Reagents, catalysts & solvents 1

HCID 962WaterSolvent2×

Procedure

2-Aminopyrazolo[1,4-a]pyridine (see Chem. Parm. Bull., 21, 2146/1973) is reacted with p-methoxybenzene diazonium salt analogously to Example 13.2. 0.53 g of the 3-azo compound obtained is suspended in 10 ml. 6N hydrochloric acid and mixed at +5° C., while stirring, with a solution of 104 mg. sodium nitrite in 0.2 ml. water. After 30 minutes, a cold solution of 198 mg. cuprous chloride in 6 ml. 6N hydrochloric acid is added thereto and the reaction mixture is stirred for 40 hours at ambient temperature. The mixture is mixed with water and extracted three or four times with ethyl acetate. After purification of the crude product by chromatography over silica gel (elution agent: ethyl acetate/ligroin 1:1 v/v), there are obtained 320 mg. of 2-chloro-3-(p-methoxyphenylazo)pyrazolo[1,5-a]pyridine (Rf =0.65; silica gel, ethyl acetate/ligroin 1:1 v/v) which is reduced with sodium dithionite analogously to Example 10.3. There is obtained the title compound; m.p. 249°-251° C. (decomp.). Rf =0.2 (silica gel, ethyl acetate/ligroin 1:1 v/v).

Workup

  1. stirringthe reaction mixture is stirred for 40 hours at ambient temperature
  2. extractionextracted three or four times with ethyl acetate
  3. customAfter purification of the crude product by chromatography over silica gel (elution agent: ethyl acetate/ligroin 1:1 v/v), there
  4. customare obtained 320 mg

Sources & evidence

ORD record
ord-eca9b99214134bf090e92f0a5b7d1c7f
Source dataset
uspto-grants-1993_08
Patent number
US05234818

Reaction notes

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