Phosphorus oxychloride → 7-Chlorofuro[2,3-c]pyridine

HRID 615869Notes

Reaction equation

[O:1]1[C:5]2[CH:6]=[CH:7][CH:8]=[N:9][C:4]=2[CH2:3][C:2]1=O.P(Cl)(Cl)([Cl:13])=O>>[Cl:13][C:4]1[N:9]=[CH:8][CH:7]=[C:6]2[CH:3]=[CH:2][O:1][C:5]=12

Participants

Reactant 2

HCID 24813Phosphorus oxychloride

HCID 13384344Furo[3,2-B]pyridin-2(3H)-one

Product 1

HCID 128261077-Chlorofuro[2,3-c]pyridine

Procedure

For example, furan-3-acrylic acid is converted to the acid azide by first reacting the acid with ethoxycarbonyl chloride and triethylamine to form the acid chloride and then reacting the mixed anhydride with sodium azide in water. The furan-3-acrylic acid azide is then heated in diphenylmethane with tributylamine to a temperature of about 190° C. to about 210° C. to form the furopyridone represented by the formula ##STR12## The furopyridone is allowed to react with phosphorus oxychloride to form 7-chlorofuro[2,3-c]pyridine and the latter is reductively dechlorinated with zinc in acetic acid to provide furo[2,3-c]pyridine.

Sources & evidence

ORD record: ord-8ffb37bfbda94792bdb48799d3a93f93
Source dataset: uspto-grants-1985_02
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US04501739

Reaction notes

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