2,2-Dimethoxypropane → 3H,5H-Pyrrolo[1,2-c]oxazol-5-one, tetrahydro-3,3-dimethyl-, (R)-

HRID 2202708Notes

Reaction equation

HRID 2202708 reaction equation
[OH:1][CH2:2][C@@H:3]1[NH:7][C:6](=[O:8])[CH2:5][CH2:4]1.CO[C:11](OC)([CH3:13])[CH3:12]>C1(C)C=CC=CC=1.C1(C)C=CC(S(O)(=O)=O)=CC=1>[CH3:12][C:11]1([CH3:13])[N:7]2[C:6](=[O:8])[CH2:5][CH2:4][C@@H:3]2[CH2:2][O:1]1

Participants

5

Reactant 2

HCID 64952,2-Dimethoxypropane2×HCID 7128291(R)-(-)-5-(Hydroxymethyl)-2-pyrrolidinone

Product 1

HCID 137469293H,5H-Pyrrolo[1,2-c]oxazol-5-one, tetrahydro-3,3-dimethyl-, (R)-Yield 103%

Reagents, catalysts & solvents 2

HCID 6101p-Toluenesulfonic acidCatalystHCID 1140TolueneSolvent

Procedure

To a stirred suspension of (R)-(−)-5-(hydroxymethyl)-2-pyrrolidinone (2.20 g, 19.11 mmol) and p-toluenesulfonic acid (0.018 g, 0.096 mmol) in toluene (54.6 ml), 2,2-dimethoxypropane (7.02 ml, 57.3 mmol) was added and the reaction was refluxed for 2 h. The reaction was equipped with a Dean-Stark then 2,2-dimethoxypropane (7.02 ml, 57.3 mmol) was added and the reaction was refluxed overnight. Solvent was evaporated to afford (R)-3,3-dimethyltetrahydropyrrolo[1,2-c]oxazol-5(3H)-one (3.04 g, 19.59 mmol, 103% yield) as yellow oil. 1H NMR (400 MHz, CDCl3) δ 4.27 (tt, J=6.01, 9.00 Hz, 1H), 4.09 (dd, J=5.65, 8.24 Hz, 1H), 3.43-3.50 (m, 1H), 2.81 (ddd, J=8.53, 12.19, 16.65 Hz, 1H), 2.55 (ddd, J=1.01, 9.15, 16.64 Hz, 1H), 2.13-2.23 (m, 1H), 1.72-1.80 (m, 1H), 1.66-1.72 (m, 3H), 1.48 (s, 3H).

Workup

  1. additionwas added
  2. temperaturethe reaction was refluxed for 2 h
  3. customThe reaction was equipped with a Dean-Stark
  4. temperaturethe reaction was refluxed overnight
  5. customSolvent was evaporated

Sources & evidence

ORD record
ord-f95c5200f0ba47eb8c8a807011c07eb5
Source dataset
uspto-grants-2016_06
Patent number
US09365522B2

Reaction notes

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