Oxalic Acid → 2-Oxa-6-azaspiro(3.3)heptane hemioxalate

HRID 1410089Notes

Reaction equation

HRID 1410089 reaction equation
C1(C)C=CC(S([N:10]2[CH2:16][C:12]3([CH2:15][O:14][CH2:13]3)[CH2:11]2)(=O)=O)=CC=1.[Mg].O.O.O.O.O.O.O.O.O.O.S([O-])([O-])(=O)=O.[Na+].[Na+].S([O-])([O-])(=O)=O.[Na+].[Na+].[C:43]([OH:48])(=[O:47])[C:44]([OH:46])=[O:45]>CO.C(O)C.C(OCC)C>[C:43]([OH:48])(=[O:47])[C:44]([OH:46])=[O:45].[CH2:13]1[C:12]2([CH2:16][NH:10][CH2:11]2)[CH2:15][O:14]1.[CH2:13]1[C:12]2([CH2:16][NH:10][CH2:11]2)[CH2:15][O:14]1

Participants

9

Reactant 5

HCID 971Oxalic AcidHCID 24436Sodium SulfateHCID 62649Sodium sulfate decahydrateHCID 5462224MagnesiumHCID 233198916-Tosyl-2-oxa-6-azaspiro[3.3]heptane

Product 1

HCID 545944422-Oxa-6-azaspiro(3.3)heptane hemioxalateYield 48.6%

Reagents, catalysts & solvents 3

HCID 702EthanolSolventHCID 887MethanolSolventHCID 3283Diethyl EtherSolvent

Procedure

6-(Toluene-4-sulfonyl)-2-oxa-6-azaspiro[3.3]heptane (510 mg, 2 mmol) and magnesium granular (336 mg, 14 mmol) were sonicated for one hour in methanol (100 ml). Almost all solvent was removed from the grey reaction mixture on a rotary evaporator to give a viscous grey residue. Diethyl ether (10 ml) and sodium sulfate decahydrate (1 g) were added and the resulting light grey mixture was stirred vigorously for 30 minutes before filtration. The filtrate was dried over anhydrous sodium sulfate and anhydrous oxalic acid (90 mg, 1 mmol) dissolved in Ethanol (˜0.5 mL) was added to the organic phase. A thick white precipitate formed instantly. It was filtered off and dried under vacuum to give 2-oxa-6-azaspiro[3.3]heptane hemioxalate (140 mg, 37%) off-white solid. 1H NMR (300 MHz, CDCl3) δ 4.64 (s, 4H), 4.11 (s, 4H).

Workup

  1. customAlmost all solvent was removed from the grey reaction mixture on a rotary evaporator
  2. customto give a viscous grey residue
  3. additionwas added to the organic phase
  4. customA thick white precipitate formed instantly
  5. filtrationIt was filtered off
  6. customdried under vacuum

Sources & evidence

ORD record
ord-3c7d69d300d24b5597632f3b12fba562
Source dataset
uspto-grants-2014_12
Patent number
US08921383B2

Reaction notes

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