Ethanol → Ethyl Chroman-2-carboxylate

HRID 1534660Notes

Reaction equation

HRID 1534660 reaction equation
[O:1]1[C:10]2[C:5](=[CH:6][CH:7]=[CH:8][CH:9]=2)[CH2:4][CH2:3][CH:2]1[C:11]([OH:13])=[O:12].[CH2:14](O)[CH3:15].OS(O)(=O)=O>C(Cl)Cl.O>[O:1]1[C:10]2[C:5](=[CH:6][CH:7]=[CH:8][CH:9]=2)[CH2:4][CH2:3][CH:2]1[C:11]([O:13][CH2:14][CH3:15])=[O:12]

Participants

6

Reactant 3

HCID 702EthanolHCID 1118Sulfuric AcidHCID 27236653,4-dihydro-2H-1-benzopyran-2-carboxylic acid

Product 1

HCID 12909094Ethyl Chroman-2-carboxylate

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 6344DichloromethaneSolvent

Procedure

Chroman-2-carboxylic acid (35.6 g, 0.2 mol) prepared according to the method of Augstein et al., J. Med. Chem., v. 11, pp. 844-848, 1968) and absolute ethanol (24.3 g, 0.6 mol) were combined in 300 ml of CH2Cl2. H2SO4 (0.6 ml, 96%) was added and the mixture gently refluxed for 21 hours, then cooled and diluted with 500 ml H2O. The organic layer was separated, washed with saturated NaHCO3 and then H2O, dried (MgSO4) and stripped to yield present title product as an oil; 38.6 g (93%); 1H-NMR (CDCl3), 300 MHz) delta 7.12 (t, 1H), 7.02 (d, 1H), 6.92 (d, 1H), 6.85 (t, 1H), 4.71 (q, 1H), 4.25 (q. 2H), 2.80 (m, 2H), 2.22 (m, 2H), 1.29 (t, 3H).

Workup

  1. temperaturethe mixture gently refluxed for 21 hours
  2. temperaturecooled
  3. customThe organic layer was separated
  4. washwashed with saturated NaHCO3
  5. dry with materialH2O, dried (MgSO4)

Sources & evidence

ORD record
ord-e61dc519ad5d472780924abe6e982373
Source dataset
uspto-grants-1992_02
Patent number
US05089637

Reaction notes

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