Sodium Dithionite → Pyrazolo[1,5-A]pyridine-2,3-diamine

HRID 260019Notes

Reaction equation

HRID 260019 reaction equation
[NH2:1][C:2]1[CH:10]=[C:5]2[CH:6]=[CH:7][CH:8]=[CH:9][N:4]2[N:3]=1.COC1C=CC([N+:19]#N)=CC=1.S(S([O-])=O)([O-])=O.[Na+].[Na+]>>[NH2:1][C:2]1[C:10]([NH2:19])=[C:5]2[CH:6]=[CH:7][CH:8]=[CH:9][N:4]2[N:3]=1

Participants

4

Reactant 3

HCID 24489Sodium DithioniteHCID 1018284-MethoxybenzenediazoniumHCID 21867001Pyrazolo[1,5-a]pyridin-2-amine

Product 1

HCID 19743463Pyrazolo[1,5-A]pyridine-2,3-diamine

Procedure

2.66 g. 2-Aminopyrazolo[1,5-a]pyridine (see Chem. Pharm. Bull., 21, 2146/1973) are reacted with p-methoxybenzenediazonium salt analogously to Example 12.3.1, the resultant azo compound is reduced with sodium dithionite and the crude product obtained is purified to give 2,3-diaminopyrazolo[1,5-a]pyridine; m.p. 190° C.; Rf =0.6 (silica gel, ligroin/acetone/glacial acetic acid 60:40:1 v/v/v).

Workup

  1. customthe crude product obtained
  2. customis purified

Sources & evidence

ORD record
ord-0684f11e6e4f427ea435aa381f06b066
Source dataset
uspto-grants-1996_06
Patent number
US05525480

Reaction notes

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