Diethyl Oxalate → HCID 178473037, compound

HRID 2293524Notes

Reaction equation

HRID 2293524 reaction equation
[O:1]1[C:10]2[C:5](=[CH:6][CH:7]=[CH:8][CH:9]=2)[C:4](=[O:11])[CH2:3][CH2:2]1.[C:12](OCC)(=[O:18])[C:13]([O:15][CH2:16][CH3:17])=[O:14]>C1COCC1.Cl>[CH2:16]([O:15][C:13](=[O:14])[C:12]([OH:18])=[C:3]1[C:4](=[O:11])[C:5]2[C:10](=[CH:9][CH:8]=[CH:7][CH:6]=2)[O:1][CH2:2]1)[CH3:17]

Participants

5

Reactant 2

HCID 7268Diethyl OxalateHCID 68110Chromanone

Product 1

HCID 178473037HCID 178473037, compoundYield 97%

Reagents, catalysts & solvents 2

HCID 313Hydrochloric AcidSolventHCID 8028TetrahydrofuranSolvent2×

Conditions

Temperature
-78 °C

Procedure

A solution of sodium 1,1,1,3,3,3-hexamethyldisilylazide (1.0 mol dm-3 ; 35 cm3) in THF was added at -78° C. under nitrogen to a stirred solution of 4-chromanone (5.0 g) in dry THF (100 cm3). The bright orange solution was stirred at -78° C. for 20 minutes, followed by addition of diethyl oxalate (4.75 cm3). The mixture was warmed to room temperature, becoming a thick, red gel. The gel was diluted with hydrochloric acid (1.0 mol dm-3 ; 200 cm3) and extracted with ethyl acetate (200 cm3). The extracts were dried (MgSO4), filtered and concentrated to give hydroxy-(4-oxo-chroman-3-ylidene)-acetic acid ethyl ester (8.3 g; 97%) as a bright yellow, waxy solid; δH (250 MHz; d6 -DMSO) 1.30 (3H, t, J 7.5, CO2 CH2CH3), 4.30 (2H, q, J 7.5, CO2CH2CH3), 5.18 (2H, s, OCH2C), 7.04 (1H, d, J 8.5, 1 of ArH), 7.12 (1H, dd, J 8.5 and 8.5, 1 of ArH), 7.58 (1H, dd, J 8.5 and 8.5, 1 of ArH) and 7.79 (1H, d, J8.5, 1 of ArH); m/z (CI+ ; NH3) 249 (MH+ ; 28%) and 205 (100).

Workup

  1. temperatureThe mixture was warmed to room temperature
  2. extractionextracted with ethyl acetate (200 cm3)
  3. dry with materialThe extracts were dried (MgSO4)
  4. filtrationfiltered
  5. concentrationconcentrated

Sources & evidence

ORD record
ord-6ffd3ffa22bd4c46b4eb18fe9ccf7e9e
Source dataset
uspto-grants-1997_11
Patent number
US05686480

Reaction notes

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