Pivaloyl chloride → HCID 502058, compound

HRID 841097Notes

Reaction equation

HRID 841097 reaction equation
[OH:1][C:2]1[CH:11]=[C:10]([OH:12])[CH:9]=[C:8]2[C:3]=1[C:4]([CH2:14][CH2:15][CH3:16])=[CH:5][C:6](=[O:13])[O:7]2.[C:17](Cl)(=[O:22])[C:18]([CH3:21])([CH3:20])[CH3:19]>N1C=CC=CC=1.C1COCC1>[C:17]([O:1][C:2]1[CH:11]=[C:10]([O:12][C:17](=[O:22])[C:18]([CH3:21])([CH3:20])[CH3:19])[CH:9]=[C:8]2[C:3]=1[C:4]([CH2:14][CH2:15][CH3:16])=[CH:5][C:6](=[O:13])[O:7]2)(=[O:22])[C:18]([CH3:21])([CH3:20])[CH3:19]

Participants

5

Reactant 2

HCID 62493Pivaloyl chloride2×HCID 53912605,7-Dihydroxy-4-propylcoumarin

Product 1

HCID 502058HCID 502058, compoundYield 177.9%

Reagents, catalysts & solvents 2

HCID 1049PyridineSolventHCID 8028TetrahydrofuranSolvent

Procedure

To a solution of 5,7-dihydroxy-4-propylcoumarin (2) (1.10 g, 5 mmol) in pyridine (12 mL) and THF (6 mL) was added pivaloyl chloride (0.673 mL, 5.5 mmol) and the reaction mixture was allowed to stir at room temperature for 24 h. TLC revealed formation of a new less polar spot and unreacted starting material. In an effort to drive the reaction to completion, pivaloyl chloride (0.50 mL) was added and the reaction continued to stir at room temperature for another 72 h. The pyridinium hydrochloride was removed by filtration and washed a few times with ethyl acetate. The organic solutions were combined and washed, successively, with 1 M HCl (2×25 mL), water (25 mL), aqueous saturated sodium bicarbonate (25 mL). After being dried over sodium sulfate and concentrated under vacuum, the crude product was purified by silica gel chromatography (2:1 hexane/ethyl acetate) to obtain 8b as a white solid (1.90 g, 98% yield). mp 110-112° C.; Rf=0.49 (4:1 hexane/ethyl acetate); 1H-NMR (CDCl3),: 1.03 (3H, t, J=7.8 Hz), 1.36 (9H, s), 1.41 (9H, s), 1.69 (2H, sextet, J=7.4 Hz), 2.81 (2H, t, J=7.8 Hz), 6.22 (1H, s), 6.60 (1H, d, J=2.4 Hz), 7.03 (1H, d, J=2.1 Hz); 13C-NMR (CDCl3): 13.5, 20.7, 26.4, 26.8, 26.9, 36.4, 39.2, 39.4, 108.6, 111.5, 113.4, 114.2, 149.4, 152.7, 154.9, 155.4, 159.9, 177.1; IR (film): 3090, 2971, 2941, 2876, 1757, 1615, 1481, 1422, 1273 cm−1; MS m/e 389 (M+1); Anal. Calcd. for C22H28O6: C, 68.02; H, 7.26. Found: C, 67.77; H, 7.18.

Workup

  1. additionwas added
  2. stirringto stir at room temperature for another 72 h
  3. customThe pyridinium hydrochloride was removed by filtration
  4. washwashed a few times with ethyl acetate
  5. washwashed
  6. dry with materialAfter being dried over sodium sulfate
  7. concentrationconcentrated under vacuum
  8. customthe crude product was purified by silica gel chromatography (2:1 hexane/ethyl acetate)

Sources & evidence

ORD record
ord-12e163942c164bd380269f180d274476
Source dataset
uspto-grants-2002_04
Patent number
US06369241B1

Reaction notes

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