Formaldehyde → 6-Methoxy-3,4-dihydro-1H-2-benzopyran-1-one

HRID 1887545Notes

Reaction equation

HRID 1887545 reaction equation
[CH2:1]([Li])CCC.C(NC(C)C)(C)C.[CH3:13][O:14][C:15]1[CH:23]=[CH:22][C:18]([C:19]([OH:21])=[O:20])=[C:17]([CH3:24])[CH:16]=1.C=O>CCCCCC.C1COCC1.O>[CH3:13][O:14][C:15]1[CH:16]=[C:17]2[C:18](=[CH:22][CH:23]=1)[C:19](=[O:21])[O:20][CH2:1][CH2:24]2

Participants

8

Reactant 4

HCID 712FormaldehydeHCID 7912DiisopropylamineHCID 5972164-Methoxy-2-methylbenzoic acidHCID 178418339Butyllithium

Product 1

HCID 124011826-Methoxy-3,4-dihydro-1H-2-benzopyran-1-one

Reagents, catalysts & solvents 3

HCID 962WaterSolventHCID 8028TetrahydrofuranSolvent2×HCID 8058HexaneSolvent

Procedure

A 1.6M solution of n-butyllithium in hexane (145.9 mL) was added dropwise to a solution of diisopropylamine (33.5 mL) in dry THF (190 mL) at −78° C. The reaction mixture was then warmed to room temperature for 5 min and again cooled to −78° C., and a solution of 4-methoxy-2-methylbenzoic acid in dry THF (210 mL) was added dropwise. After stirring at this temperature for 10 min, paraformaldehyde (7 g) was added. The reaction mixture was then allowed to reach room temperature and was stirred at this temperature for 4 h. Water was added to the reaction mixture, and then the THF was removed in vacuo and the aqueous phase was extracted with diethyl ether. The aqueous phase was acidified with conc. HCl, and the resulting precipitate was filtered off and washed with water several times. The product with the molecular weight of 178.06 (C10H10O3) was obtained in this way; MS (ESI): 179 (M+H+).

Workup

  1. temperatureagain cooled to −78° C.
  2. customto reach room temperature
  3. stirringwas stirred at this temperature for 4 h
  4. customthe THF was removed in vacuo
  5. extractionthe aqueous phase was extracted with diethyl ether
  6. filtrationthe resulting precipitate was filtered off
  7. washwashed with water several times
  8. customThe product with the molecular weight of 178.06 (C10H10O3) was obtained in this way

Sources & evidence

ORD record
ord-e15a35bf3666477b9f2686c170eaecf4
Source dataset
uspto-grants-2013_08
Patent number
US08501771B2

Reaction notes

Loading…