Pyrrolidine → 6-Bromo-3-methyl-2',4',5',6'-tetrahydrospiro[chroman-2,3'-pyran]-4-one

HRID 2096542Notes

Reaction equation

HRID 2096542 reaction equation
[Br:1][C:2]1[CH:3]=[CH:4][C:5](O)=[C:6]([C:8](=[O:11])[CH2:9][CH3:10])[CH:7]=1.[O:13]1[CH2:18][CH2:17][CH2:16][C:15](=[O:19])[CH2:14]1.N1CCCC1>CO>[Br:1][C:2]1[CH:7]=[C:6]2[C:5](=[CH:4][CH:3]=1)[O:19][C:15]1([CH2:16][CH2:17][CH2:18][O:13][CH2:14]1)[CH:9]([CH3:10])[C:8]2=[O:11]

Participants

5

Reactant 3

HCID 31268PyrrolidineHCID 901092H-Pyran-3(4H)-one, dihydro-HCID 7364091-(5-Bromo-2-hydroxyphenyl)propan-1-one

Product 1

HCID 584240286-Bromo-3-methyl-2',4',5',6'-tetrahydrospiro[chroman-2,3'-pyran]-4-oneYield 16%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

A mixture of 1-(5-bromo-2-hydroxyphenyl)propan-1-one (5.7 g, 25 mol), dihydro-2H-pyran-3(4H)-one (5 g, 50 mmol) and pyrrolidine (3.4 g, 48 mmol) in methanol (80 mL) was stirred overnight. The reaction mixture was removed in vacuo, and H2O was added. The resulting solution was extracted with ethyl acetate. The ethyl acetate solution was dried over anhydrous Na2SO4, filtered, and evaporated to give 6-bromo-3-methyl-2′,4′,5′,6′-tetrahydrospiro[chroman-2,3′-pyran]-4-one (1.2 g, 16%). 1HNMR (CDCl3): 1.16-1.27 (m, 3H), 1.51-1.57 (m, 1H), 1.66-1.73 (m, 1H), 1.91-2.08 (m, 2H), 2.59-2.69 (m, 1H), 3.46-3.56 (m, 2H), 3.88-3.98 (m, 2H), 6.97 (m, 1H), 7.58 (m, 1H), 7.95 (s, 1H).

Workup

  1. customThe reaction mixture was removed in vacuo, and H2O
  2. additionwas added
  3. extractionThe resulting solution was extracted with ethyl acetate
  4. dry with materialThe ethyl acetate solution was dried over anhydrous Na2SO4
  5. filtrationfiltered
  6. customevaporated

Sources & evidence

ORD record
ord-cdb023ff198f4281a52c55566bdca29c
Source dataset
uspto-grants-2013_05
Patent number
US08450308B2

Reaction notes

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