Pyridine → 6-Chloro[1,3]oxazolo[4,5-b]pyridin-2(3H)-one

HRID 258570Notes

Reaction equation

HRID 258570 reaction equation
[C:1](Cl)(Cl)=[O:2].N1C=CC=CC=1.[NH2:11][C:12]1[C:17]([OH:18])=[CH:16][C:15]([Cl:19])=[CH:14][N:13]=1>C(Cl)(Cl)Cl>[Cl:19][C:15]1[CH:16]=[C:17]2[O:18][C:1](=[O:2])[NH:11][C:12]2=[N:13][CH:14]=1

Participants

5

Reactant 3

HCID 1049PyridineHCID 6371PhosgeneHCID 103132002-Amino-5-chloropyridin-3-ol

Product 1

HCID 136144596-Chloro[1,3]oxazolo[4,5-b]pyridin-2(3H)-oneYield 85%

Reagents, catalysts & solvents 1

HCID 6212ChloroformSolvent

Procedure

Phosgene is introduced at 40°-50° C., after the addition of 20 parts of pyridine, into a solution of 10 parts of 2-amino-3-hydroxy-5-chloropyridine in 200 parts of chloroform, and stirring is maintained for one hour at room temperature; the chloroform and the pyridine are evaporated off in a water-jet vacuum, and ice-water is added to the residue. The precipitate is filtered off and dried at 40°-50° C. in vacuo. There are obtained 10 parts of 6-chloro-oxazolo[4,5-b]pyridin-2-(3H)-one (85% of theory), m.p. 184°-186° C.

Workup

  1. customthe chloroform and the pyridine are evaporated off in a water-jet vacuum, and ice-water
  2. additionis added to the residue
  3. filtrationThe precipitate is filtered off
  4. customdried at 40°-50° C. in vacuo

Sources & evidence

ORD record
ord-0ebbbff502d242e8b9f6173ae8e7551a
Source dataset
uspto-grants-1977_07
Patent number
US04033975

Reaction notes

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