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

HRID 1995897Notes

Reaction equation

HRID 1995897 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

3

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 13384344Furo[3,2-B]pyridin-2(3H)-one

Product 1

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

Procedure

Alternatively, furan-3-aldehyde is converted to furan-3-acrylic acid with acetic anhydride and potassium carbonate and the acid 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 ##STR11## 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-771b78a5855a49418087940178458a0c
Source dataset
uspto-grants-1983_09
Patent number
US04406898

Reaction notes

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