Phosphorus oxychloride → HCID 86735321, compound

HRID 1833348Notes

Reaction equation

O[C:2]1[C:7]2[C:8]([CH3:16])=[N:9][C:10]3[N:11]([N:12]=[C:13]([CH3:15])[CH:14]=3)[C:6]=2[N:5]=[CH:4][C:3]=1[C:17]([O:19][CH2:20][CH3:21])=[O:18].P(Cl)(Cl)([Cl:24])=O>>[Cl:24][C:2]1[C:7]2[C:8]([CH3:16])=[N:9][C:10]3[N:11]([N:12]=[C:13]([CH3:15])[CH:14]=3)[C:6]=2[N:5]=[CH:4][C:3]=1[C:17]([O:19][CH2:20][CH3:21])=[O:18]

Participants

Reactant 2

HCID 24813Phosphorus oxychloride

HCID 178469574HCID 178469574, compound

Product 1

HCID 86735321HCID 86735321, compound

Procedure

13.4 g. of 6-hydroxy-2,5-dimethylpyrazolo[1,5-a]pyrido[3,2-e]pyrimidine-7-carboxylic acid, ethyl ester (0.05 mol.) and 100 ml. of phosphorous oxychloride are refluxed with stirring for 5 hours. The excess of chlorinating agent is distilled off and the dark residue is poured into ice-water. 6-Chloro-2,5-dimethylpyrazolo[1,5-a]pyrido[3,2-e]pyrimidine-7-carboxylic acid, ethyl ester precipitates, yield 6.4 g. (42%), m.p. 143°-145° (ethyl acetate).

Workup

distillationThe excess of chlorinating agent is distilled off
additionthe dark residue is poured into ice-water
custom6-Chloro-2,5-dimethylpyrazolo[1,5-a]pyrido[3,2-e]pyrimidine-7-carboxylic acid, ethyl ester precipitates

Sources & evidence

ORD record: ord-ae11cba474b64cd2978f0849e0769fe7
Source dataset: uspto-grants-1978_01
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US04066643

Reaction notes

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