Sulfuric Acid → 6-Bromo-4-(chloromethyl)-7-hydroxy-2H-1-benzopyran-2-one

HRID 993351Notes

Reaction equation

HRID 993351 reaction equation
[Br:1][C:2]1[CH:8]=[CH:7][C:5]([OH:6])=[CH:4][C:3]=1[OH:9].S(=O)(=O)(O)O.[Cl:15][CH2:16][C:17](=O)[CH2:18][C:19](OCC)=[O:20]>>[Br:1][C:2]1[CH:8]=[C:7]2[C:5](=[CH:4][C:3]=1[OH:9])[O:6][C:19](=[O:20])[CH:18]=[C:17]2[CH2:16][Cl:15]

Participants

4

Reactant 3

HCID 1118Sulfuric AcidHCID 69484Ethyl 4-chloroacetoacetateHCID 811054-Bromoresorcinol

Product 1

HCID 184103446-Bromo-4-(chloromethyl)-7-hydroxy-2H-1-benzopyran-2-oneYield 59.1%

Procedure

A solution of 936.1 mg (4.953 mmol) 4-bromoresorcinol, concentrated sulfuric acid (5 mL) and ethyl 4-chloroacetoacetate (1 mL, 7.4 mmol) was stirred for 6 days at room temperature. The reaction mixture was poured into ice-water and stirred for 2 hours to give a fine precipitate. The precipitate was collected by filtration, washed with cold water and dried under vacuum over P2O5 to yield 847.6 mg (2.928 mmol, 59.1% yield) of compound 11 as a solid. 1H NMR (CD3OD) δ 7.96 (1H, s), 6.86 (1H, s), 6.43 (1H, s), 4.83 (2H, s).

Workup

  1. customto give a fine precipitate
  2. filtrationThe precipitate was collected by filtration
  3. washwashed with cold water
  4. dry with materialdried under vacuum over P2O5

Sources & evidence

ORD record
ord-373d254e516d456e830fed7d5c4f4c40
Source dataset
uspto-grants-2002_10
Patent number
US06472541B2

Reaction notes

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