Sulfuric Acid → 3-(2-Hydroxybenzylidene)dihydrofuran-2(3h)-one

HRID 2085224Notes

Reaction equation

HRID 2085224 reaction equation
[CH:1](=O)[C:2]1[C:3](=[CH:5][CH:6]=[CH:7][CH:8]=1)[OH:4].[CH3:10][O-:11].[Na+].S(=O)(=O)(O)O>C1(C)C=CC=CC=1>[OH:4][C:3]1[CH:5]=[CH:6][CH:7]=[CH:8][C:2]=1[CH:1]=[C:1]1[CH2:2][CH2:3][O:4][C:10]1=[O:11]

Participants

5

Reactant 3

HCID 1118Sulfuric AcidHCID 6998SalicylaldehydeHCID 10942334Sodium Methoxide

Product 1

HCID 2297583-(2-Hydroxybenzylidene)dihydrofuran-2(3h)-oneYield 142%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

Salicylaldehyde (293 g) and Υ-butyrolactone (413 g) were dissolved in toluene (2.4 L) and the solution was cooled to not more than 3° C. in an ice-salt bath. Thereto was added sodium methoxide (324 g) over 20 min. The temperature of the reaction mixture rose to 24° C. After stirring at room temperature for 3 hr, the mixture was stirred for 45 min under heating at 60-65° C. The reaction mixture was cooled again in an ice-bath and 10% sulfuric acid (2.51 ml) was added dropwise. The obtained white suspension was filtrated, washed with water and dried to give the title compound (324 g), melting point 162-164° C.

Workup

  1. temperaturethe solution was cooled to not more than 3° C. in an ice-salt bath
  2. customrose to 24° C
  3. stirringthe mixture was stirred for 45 min
  4. temperatureunder heating at 60-65° C
  5. temperatureThe reaction mixture was cooled again in an ice-bath
  6. filtrationThe obtained white suspension was filtrated
  7. washwashed with water
  8. customdried

Sources & evidence

ORD record
ord-6e4cc6e433fc483c89f52f0034e3195d
Source dataset
uspto-grants-2004_04
Patent number
US06720320B2

Reaction notes

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