Sulfuric Acid → 6-(4-Chlorophenyl)-4-hydroxy-2H-pyran-2-one

HRID 2393967Notes

Reaction equation

HRID 2393967 reaction equation
[H-].[Na+].[C:3]([O:9][CH2:10][CH3:11])(=[O:8])[CH2:4][C:5]([CH3:7])=[O:6].C(NC(C)C)(C)C.[Li].[Cl:20][C:21]1[CH:32]=[CH:31]C(C(N(OC)C)=O)=[CH:23][CH:22]=1.OS(O)(=O)=O>C1COCC1>[Cl:20][C:21]1[CH:32]=[CH:31][C:11]([C:10]2[O:9][C:3](=[O:8])[CH:4]=[C:5]([OH:6])[CH:7]=2)=[CH:23][CH:22]=1

Participants

7

Reactant 5

HCID 1118Sulfuric AcidHCID 8868Ethyl AcetoacetateHCID 24758Sodium hydrideHCID 112756634-Chloro-N-methoxy-N-methylbenzamideHCID 45051747Lithium diisopropylamine

Product 1

HCID 546902156-(4-Chlorophenyl)-4-hydroxy-2H-pyran-2-oneYield 31%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Procedure

The title compound (1.56 g, m.p. 247°-249° C.) was prepared in a similar manner as that demonstrated in the preparation of Example N using the following: 60% NaH (0.904 g, 22.6 mmol), THF (50 mL), ethyl acetoacetate (3.00 g, 22.6 mmol), lithium diisopropylamine in THF (39.8 mL, 24 mmol), 4-chloro-N-methoxy-N-methylbenzamide (3.73 g, 22.6 mmol), 90% H2SO4 (20 mL). H NMR (300 MHz, DMSO-d6) δ 11.950 (bs, 1 H), 7.878 (d, 1 H, J=9 Hz), 7.584 (d, 1 H, J=9 Hz), 6.812 (d, 1 H, J=2 Hz), 5.409 (d, 1 H, J=2 Hz).

Workup

  1. customthat demonstrated in the preparation of Example N

Sources & evidence

ORD record
ord-2cd932d7d68b40e6b981a42bb2ecb213
Source dataset
uspto-grants-1998_09
Patent number
US05808062

Reaction notes

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