Phosphorus oxychloride → HCID 178469780, compound

HRID 1287260Notes

Reaction equation

HRID 1287260 reaction equation
[CH2:1]([O:3][C:4]([C:6]1[C:7]2[NH:15][N:14]=[C:13]([CH3:16])[C:8]=2[C:9](O)=[N:10][CH:11]=1)=[O:5])[CH3:2].P(Cl)(Cl)([Cl:19])=O>>[CH2:1]([O:3][C:4]([C:6]1[C:7]2[NH:15][N:14]=[C:13]([CH3:16])[C:8]=2[C:9]([Cl:19])=[N:10][CH:11]=1)=[O:5])[CH3:2]

Participants

3

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 178469841HCID 178469841, compound

Product 1

HCID 178469780HCID 178469780, compound

Procedure

22.1 g. of 4-hydroxy-3-methyl-1H-pyrazolo[4,3-c]pyridine-7-carboxylic acid ethyl ester (0.1 mol.) and 100 ml. of phosphorus oxychloride are refluxed for 10 hours. After this time, the excess phosphorus oxychloride is removed by distillation. The oily residue is poured into 50 ml. of ice water. On neutralization with aqueous ammonia, 4-chloro-3-methyl-1H-pyrazolo[4,3-c]-pyridine-7-carboxylic acid ethyl ester crystallizes and is filtered. Recrystallization yields 12 g. (50%), m.p. 180°.

Workup

  1. customAfter this time, the excess phosphorus oxychloride is removed by distillation
  2. additionThe oily residue is poured into 50 ml
  3. customOn neutralization with aqueous ammonia, 4-chloro-3-methyl-1H-pyrazolo[4,3-c]-pyridine-7-carboxylic acid ethyl ester crystallizes
  4. filtrationis filtered
  5. customRecrystallization
  6. customyields 12 g

Sources & evidence

ORD record
ord-8d397cc531b0412eac7239811a0879c4
Source dataset
uspto-grants-1976_10
Patent number
US03984422

Reaction notes

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