Ammonium Chloride → Methyl 6-chloro-3-oxo-3,4-dihydro-2H-1,4-benzoxazine-8-carboxylate

HRID 329715Notes

Reaction equation

HRID 329715 reaction equation
[Cl-].[NH4+].[Cl:3][C:4]1[CH:16]=[C:15]([N+:17]([O-])=O)[C:7]([O:8][CH2:9][C:10](OCC)=[O:11])=[C:6]([C:20]([O:22][CH3:23])=[O:21])[CH:5]=1>CN(C)C=O.[Fe]>[Cl:3][C:4]1[CH:5]=[C:6]([C:20]([O:22][CH3:23])=[O:21])[C:7]2[O:8][CH2:9][C:10](=[O:11])[NH:17][C:15]=2[CH:16]=1

Participants

5

Reactant 2

HCID 25517Ammonium ChlorideHCID 14802112HCID 14802112, compound

Product 1

HCID 14771557Methyl 6-chloro-3-oxo-3,4-dihydro-2H-1,4-benzoxazine-8-carboxylateYield 90.3%

Reagents, catalysts & solvents 2

HCID 23925IronCatalystHCID 6228DimethylformamideSolvent3×

Procedure

A solution of 100 ml of aqueous 0.78N ammonium chloride and 50 ml of dimethylformamide is heated at 85° C. and 40 g of powdery iron is added thereto under stirring followed by addition of a solution of 63.5 g of ethyl 4-chloro-2-methoxycarbonyl-6-nitrophenoxyacetate in 150 ml of dimethylformamide over 15 minutes. The reaction temperature rises to 95° C. The resulting solution is stirred at 80°-90° C. for an hour and 400 ml of dimethylformamide is added thereto. The whole solution is filtered with suction through hot celite. The mother liquor is poured into 2 1 of ice-cold water and the precipitated crystals are collected by filtration to give 43.6 g of methyl 6-chloro-3,4-dihydro-3-oxo-2H-1,4-benzoxazine-8-carboxylate, melting at 239°-241° C.

Workup

  1. customrises to 95° C
  2. stirringThe resulting solution is stirred at 80°-90° C. for an hour
  3. filtrationThe whole solution is filtered with suction through hot celite
  4. additionThe mother liquor is poured into 2 1 of ice-cold water
  5. filtrationthe precipitated crystals are collected by filtration

Sources & evidence

ORD record
ord-2f67cdbe4da642418e7a759cc62410a3
Source dataset
uspto-grants-1990_01
Patent number
US04892872

Reaction notes

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