Benzyl Bromide → Cromolyn

HRID 990013Notes

Reaction equation

HRID 990013 reaction equation
[Na].[Na].[C:3]([C:6]1[O:7][C:8]2[C:13]([C:14](=[O:16])[CH:15]=1)=[C:12]([O:17][CH2:18][CH:19]([OH:36])[CH2:20][O:21][C:22]1[CH:31]=[CH:30][CH:29]=[C:28]3[C:23]=1[C:24](=[O:35])[CH:25]=[C:26]([C:32]([OH:34])=[O:33])[O:27]3)[CH:11]=[CH:10][CH:9]=2)([OH:5])=[O:4].C(Br)C1C=CC=CC=1.C(=O)([O-])O.[Na+]>CN(C=O)C>[C:32]([C:26]1[O:27][C:28]2[C:23]([C:24](=[O:35])[CH:25]=1)=[C:22]([O:21][CH2:20][CH:19]([OH:36])[CH2:18][O:17][C:12]1[CH:11]=[CH:10][CH:9]=[C:8]3[C:13]=1[C:14](=[O:16])[CH:15]=[C:6]([C:3]([OH:5])=[O:4])[O:7]3)[CH:31]=[CH:30][CH:29]=2)([OH:34])=[O:33]

Participants

5

Reactant 3

HCID 7498Benzyl Bromide2×HCID 516892Sodium BicarbonateHCID 98278341,3-Bis(2-carboxychromon-5-yloxy)-propan-2-ol disodium salt

Product 1

HCID 2882CromolynYield 70.6%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

1,3-bis(2-carboxychromon-5-yloxy)-propan-2-ol disodium salt (2.5 g, 5.2 mmol), was suspended in DMF. To the suspension was added benzyl bromide (0.734 ml, 6.2 mmol) and the reaction was kept overnight under stirring. An additional portion of benzyl bromide (0.734 ml, 6.2 mmol) was added. After 24 hr, the reaction mixture was poured into sodium hydrogen carbonate aqueous solution and extracted dichloromethane. The organic phase was washed with water two times and evaporated to give the dibenzyl ester of 1,3-bis-(2-carboxychromon-5-yloxy)propan-2-ol (1.72 g).

Workup

  1. waitAfter 24 hr
  2. extractionextracted dichloromethane
  3. washThe organic phase was washed with water two times
  4. customevaporated

Sources & evidence

ORD record
ord-3dc3c4513a864b7485e2871d15867720
Source dataset
uspto-grants-2002_10
Patent number
US06458772B1

Reaction notes

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