4-Chlororesorcinol → 6-Chloro-2,2-dimethyl-3,4-dihydro-2H-1-benzopyran-7-ol

HRID 1593549Notes

Reaction equation

HRID 1593549 reaction equation
[Cl:1][C:2]1[CH:8]=[CH:7][C:5]([OH:6])=[CH:4][C:3]=1[OH:9].[CH3:10][C:11]([CH3:16])=[CH:12][C:13](O)=O>CS(O)(=O)=O.O=P12OP3(OP(OP(O3)(O1)=O)(=O)O2)=O>[Cl:1][C:2]1[CH:8]=[C:7]2[C:5](=[CH:4][C:3]=1[OH:9])[O:6][C:11]([CH3:16])([CH3:10])[CH2:12][CH2:13]2

Participants

4

Reactant 2

HCID 17314-Chlororesorcinol2×HCID 109313-Methyl-2-butenoic acid

Product 1

HCID 586299756-Chloro-2,2-dimethyl-3,4-dihydro-2H-1-benzopyran-7-ol

Reagents, catalysts & solvents 1

HCID 86584057Phosphorus Pentoxide-Methanesulfonic AcidSolvent

Procedure

The desired 6-chloro-2,2-dimethylchroman-7-ol was synthesized from 4-chlororesorcinol as follows. A mixture of 3,3-dimethylacrylic acid (7.0 g) and 4-chlororesorcinol (10 g) in Eaton's reagent (50 mL) was stirred at ambient temperature for 16 h. At the end, the mixture was poured over ice and the precipitate was filtered, dried and crystallized from aqueous methanol to provide 6-chloro-7-hydroxy-2,2-dimethyl-2,3-dihydro-4H-chomen-4-one (8.7 g).

Workup

  1. additionAt the end, the mixture was poured over ice
  2. filtrationthe precipitate was filtered
  3. customdried
  4. customcrystallized from aqueous methanol
  5. customto provide 6-chloro-7-hydroxy-2,2-dimethyl-2,3-dihydro-4H-chomen-4-one (8.7 g)

Sources & evidence

ORD record
ord-00cc128b83b641bab976c82be462d9d4
Source dataset
uspto-grants-2007_11
Patent number
US07297715B2

Reaction notes

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