Methanesulfonic Acid → N-[(7-acetyl-9,9a-dihydro-3-oxo-1H,3H-oxazolo[3,4-a]indol-1-yl)methyl]acetamide

HRID 484407

Reaction equation

HRID 484407 reaction equation
[O:1]=[C:2]1[N:6]2[C:7]3[CH:8]=[CH:9][CH:10]=[CH:11][C:12]=3[CH2:13][CH:5]2[CH:4]([CH2:14][NH:15][C:16](=[O:18])[CH3:17])[O:3]1.CS(O)(=O)=O.[C:24](OC(=O)C)(=[O:26])[CH3:25].C(=O)(O)[O-].[Na+]>C(Cl)Cl>[C:24]([C:10]1[CH:9]=[CH:8][C:7]2[N:6]3[C:2](=[O:1])[O:3][CH:4]([CH2:14][NH:15][C:16](=[O:18])[CH3:17])[CH:5]3[CH2:13][C:12]=2[CH:11]=1)(=[O:26])[CH3:25]

Participants

6

Procedure

A mixture of (±) (1S,9aS/1R,9aR) N-[(9,9a-dihydro-3-oxo-1H,3H-oxazolo[3, 4-a]indol-1-yl)methyl]acetamide (X diastereomer B, EXAMPLE 11, 8 mg), methane sulfonic acid (0.5 ml), and acetic anhydride (10 μl) is stirred in methylene chloride (0.2 ml) from 0° to 20° for 19.5 hours. After this time the mixture is cooled in an ice bath and additional acetic anhydride (10 μl) is added. The mixture is stirred for one hour then added to a small amount of ice and saturated aqueous sodium bicarbonate (7 ml) is added, then solid sodium bicarbonate is added until alkaline. The mixture is then extracted with methylene chloride (5×, 20 ml total). The combined extract layers provide 8 mg of material. The 8 mg is then purified by chromatography (5 cm×0.5 cm disposable pipet, 40-63μ silica) eluting with 1% and 2.5% methanol/methylene chloride gradient while collecting 0.4 ml fractions. The appropriate fractions are pooled and concentrated to provide the title compound.

Workup

  1. temperatureAfter this time the mixture is cooled in an ice bath
  2. additionis added
  3. extractionThe mixture is then extracted with methylene chloride (5×, 20 ml total)
  4. extractionThe combined extract layers

Sources & evidence

ORD record
ord-95a8adc1cf0041d19d15230de9d490f8
Source dataset
uspto-grants-1993_07
Patent number
US05231188

Linked notes

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