(S)-2-ethyl-7-methoxycarbonyl-4-(2-propyl)-3-oxo-3,4-dihydro-2H-1,4-benzoxazine → (S)-2-ethyl-4-(2-propyl)-3-oxo-3,4-dihydro-2H-1,4-benzoxazine-7-carboxylic acid

HRID 234908Notes

Reaction equation

HRID 234908 reaction equation
[CH2:1]([C@H:3]1[C:8](=[O:9])[N:7]([CH:10]([CH3:12])[CH3:11])[C:6]2[CH:13]=[CH:14][C:15]([C:17]([O:19]C)=[O:18])=[CH:16][C:5]=2[O:4]1)[CH3:2]>Cl>[CH2:1]([C@H:3]1[C:8](=[O:9])[N:7]([CH:10]([CH3:12])[CH3:11])[C:6]2[CH:13]=[CH:14][C:15]([C:17]([OH:19])=[O:18])=[CH:16][C:5]=2[O:4]1)[CH3:2]

Participants

3

Reactant 1

HCID 10826379(S)-2-ethyl-7-methoxycarbonyl-4-(2-propyl)-3-oxo-3,4-dihydro-2H-1,4-benzoxazine

Product 1

HCID 10515674(S)-2-ethyl-4-(2-propyl)-3-oxo-3,4-dihydro-2H-1,4-benzoxazine-7-carboxylic acidYield 86.7%

Reagents, catalysts & solvents 1

HCID 313Hydrochloric AcidSolvent

Procedure

A mixture of (S)-2-ethyl-7-methoxycarbonyl-4-(2-propyl)-3-oxo-3,4-dihydro-2H-1,4-benzoxazine (0.85 g) in concentrated hydrochloric acid (20 ml) was stirred under reflux for a day. The concentrated hydrochloric acid was distilled off under reduced pressure. Water was added to the residue and extraction with ethyl acetate was conducted. The extract was washed with water and then the solvent was distilled off under reduced pressure to give (S)-2-ethyl-4-(2-propyl)-3-oxo-3,4-dihydro-2H-1,4-benzoxazine-7-carboxylic acid (0.70 g).

Workup

  1. temperatureunder reflux for a day
  2. distillationThe concentrated hydrochloric acid was distilled off under reduced pressure
  3. additionWater was added to the residue and extraction with ethyl acetate
  4. washThe extract was washed with water
  5. distillationthe solvent was distilled off under reduced pressure

Sources & evidence

ORD record
ord-8bcb9cf13bc4412ab1a640c5e6030511
Source dataset
uspto-grants-1997_01
Patent number
US05597820

Reaction notes

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