Water → 1H,3H,4H-Pyrrolo[2,1-c][1,4]oxazine-8-carboxylic acid

HRID 926363Notes

Reaction equation

HRID 926363 reaction equation
C([O:3][C:4]([C:6]1[CH:7]=[CH:8][N:9]2[CH2:14][CH2:13][O:12][CH2:11][C:10]=12)=[O:5])C.O.[OH-].[Na+]>CO>[CH2:11]1[C:10]2=[C:6]([C:4]([OH:5])=[O:3])[CH:7]=[CH:8][N:9]2[CH2:14][CH2:13][O:12]1

Participants

5

Reactant 3

HCID 962WaterHCID 14798Sodium HydroxideHCID 897268463,4-dihydro-1H-pyrrolo[2,1-c][1,4]oxazine-8-carboxylic acid ethyl ester

Product 1

HCID 825972611H,3H,4H-Pyrrolo[2,1-c][1,4]oxazine-8-carboxylic acidYield 100%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

To a solution of 3,4-dihydro-1H-pyrrolo[2,1-c][1,4]oxazine-8-carboxylic acid ethyl ester (Comp. No. 2a) (3.2 g, 16.4 mmol) in methanol (64 ml) was added water (64 ml) and sodium hydroxide (3.3 g, 82 mmol) and the mixture was stirred at reflux until complete conversion according to LC/MC (about 4 h). Approximately half of the solvents were evaporated in vacuo and the mixture was acidified with excess hydrochloric acid. The forming precipitate was filtered off, washed once with water and dried in vacuo to give 2.7 g (100%) of 3,4-dihydro-1H-pyrrolo[2,1-c][1,4]oxazine-8-carboxylic acid as white solid. LC/MS (method 4): Rt=0.77 min; m/z=168.02 (M+H+).

Workup

  1. temperatureat reflux until complete conversion
  2. customaccording to LC/MC (about 4 h)
  3. customApproximately half of the solvents were evaporated in vacuo
  4. filtrationThe forming precipitate was filtered off
  5. washwashed once with water
  6. customdried in vacuo

Sources & evidence

ORD record
ord-951b45902add4d0b88cbc51240449200
Source dataset
uspto-grants-2016_03
Patent number
US09284333B2

Reaction notes

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