Water → tert-butyl 7-(benzyloxy)-2H-chromene-3-carboxylate

HRID 268694Notes

Reaction equation

HRID 268694 reaction equation
[CH2:1]([O:8][C:9]1[CH:16]=[CH:15][C:12]([CH:13]=O)=[C:11]([OH:17])[CH:10]=1)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.C([O-])([O-])=O.[K+].[K+].[C:24]([O:28][C:29]([CH3:32])([CH3:31])[CH3:30])(=[O:27])[CH:25]=[CH2:26].O>CN1C(=O)CCC1>[CH2:1]([O:8][C:9]1[CH:10]=[C:11]2[C:12]([CH:13]=[C:25]([C:24]([O:28][C:29]([CH3:32])([CH3:31])[CH3:30])=[O:27])[CH2:26][O:17]2)=[CH:15][CH:16]=1)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1

Participants

6

Reactant 4

HCID 962WaterHCID 11430Potassium CarbonateHCID 15458tert-Butyl acrylateHCID 5612354-Benzyloxy-2-hydroxybenzaldehyde

Product 1

HCID 59832107tert-butyl 7-(benzyloxy)-2H-chromene-3-carboxylateYield 77%

Reagents, catalysts & solvents 1

HCID 13387N-methyl-2-pyrrolidoneSolvent

Conditions

Temperature
155 °C

Procedure

To a stirred solution of 4-benzyloxy-2-hydroxy benzaldehyde (11.41 g, 50 mmol) in NMP (30 ml) was added K2CO3 (13.0 g, 100 mmol) and heated to 155° C. under N2 atmosphere. t-Butyl acrylate (36.5 ml, 250 mmol) was divided into 4 portions (10, 10, 10 & 6.5 ml). First 10 ml was added to the reaction mixture and heated at 155° C. The rest were added after 2 hr intervals and the reaction mixture was heated for total of 8 hrs. The reaction mixture was cooled to room temperature and water (150 ml) was added. The product was extracted with 150 ml of ether. The ether layer was washed with water twice and dried. Ether layer was diluted with 50% hexanes and passed through a pad of silica (3 inch length and 4 inch diameter). The silica was washed with 50% ether/hexane mixture and the solvent was evaporated to give the product as pale yellow solid (13 g, 77%).

Workup

  1. additionFirst 10 ml was added to the reaction mixture
  2. temperatureheated at 155° C
  3. additionThe rest were added after 2 hr intervals
  4. temperaturethe reaction mixture was heated for total of 8 hrs
  5. temperatureThe reaction mixture was cooled to room temperature
  6. extractionThe product was extracted with 150 ml of ether
  7. washThe ether layer was washed with water twice
  8. customdried
  9. additionEther layer was diluted with 50% hexanes
  10. washThe silica was washed with 50% ether/hexane mixture
  11. customthe solvent was evaporated

Sources & evidence

ORD record
ord-1530c88b49d249608f4c768f6c850877
Source dataset
uspto-grants-2008_11
Patent number
US07446127B2

Reaction notes

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