Diisopropylamine → (E)-2,2-Dimethyl-5-[2-[4-(methylthio)phenyl]ethenyl]-3(2H)-furanone

HRID 1085571Notes

Reaction equation

HRID 1085571 reaction equation
[CH:1](NC(C)C)([CH3:3])[CH3:2].[CH2:8]([Li])[CH2:9][CH2:10][CH3:11].[CH3:13][C:14]1([CH3:21])[C:18](=[O:19])[CH:17]=[C:16]([CH3:20])[O:15]1.CC1C=CC([CH:27]=[S:28])=CC=1.FC(F)(F)C(OC(=O)C(F)(F)F)=O>O1CCCC1.CCCCCC.C(N(CC)CC)C.CN(C)P(N(C)C)(N(C)C)=O>[CH3:13][C:14]1([CH3:21])[C:18](=[O:19])[CH:17]=[C:16](/[CH:20]=[CH:11]/[C:10]2[CH:3]=[CH:1][C:2]([S:28][CH3:27])=[CH:8][CH:9]=2)[O:15]1

Participants

10

Reactant 5

HCID 7912DiisopropylamineHCID 9845Trifluoroacetic anhydrideHCID 1370803(2H)-Furanone, 2,2,5-trimethyl-HCID 181775354-MethylthiobenzaldehydeHCID 178418339Butyllithium

Product 1

HCID 15086688(E)-2,2-Dimethyl-5-[2-[4-(methylthio)phenyl]ethenyl]-3(2H)-furanoneYield 48%

Reagents, catalysts & solvents 4

HCID 8028TetrahydrofuranSolvent3×HCID 8058HexaneSolventHCID 8471TriethylamineSolventHCID 12679HexamethylphosphoramideSolvent

Procedure

To a solution of dry diisopropylamine (5.0 mL, 35.7 mM) in dry tetrahydrofuran (150 mL) at -78° C., was added dropwise a 2.3N solution of n-butyllithium in hexane (15.5 mL, 35.7 mM). After the reaction solution was stirred for 15 minutes, a solution of 2,2,5-trimethyl-3(2H)-furanone (30 g, 23.8 mM) in tetrahydrofuran (25 mL) was added dropwise. Hexamethylphosphoramide (6.4 mL, 34.7 mM) was then added dropwise after 30 minutes. Finally, p-methylthiobenzaldehyde (43 g, 28.5 mM) in tetrahydrofuran (25 mL) was added in one portion. The reaction solution was stirred 15 minutes when trifluroacetic anhydride (10.5 mL, 75 mM) was added in one portion. Again, the reaction solution was stirred 15 minutes when triethylamine (5.9 mL, 48 mM) was added and was allowed to warm to room temperature. Then the reaction mixture was partitioned between saturated aqueous sodium chloride (50 mL) and diethyl ether (50 mL). The organic layer was separated and washed with saturated aqueous sodium bicarbonate (2×25 mL) and saturated aqueous sodium chloride (25 mL). The organic layer was dried over magnesium sulfate, filtered and concentrated under reduced pressure to give an amber liquid. The crude product was purified by chromatography (silica gel, pet. ether-ethyl acetate) to afford yellow crystals (3.0 g, 48% yield), m.p. 98°-99.5° C.

Workup

  1. additionwas added in one portion
  2. additionwas added
  3. customThen the reaction mixture was partitioned between saturated aqueous sodium chloride (50 mL) and diethyl ether (50 mL)
  4. customThe organic layer was separated
  5. washwashed with saturated aqueous sodium bicarbonate (2×25 mL) and saturated aqueous sodium chloride (25 mL)
  6. dry with materialThe organic layer was dried over magnesium sulfate
  7. filtrationfiltered
  8. concentrationconcentrated under reduced pressure
  9. customto give an amber liquid
  10. customThe crude product was purified by chromatography (silica gel, pet. ether-ethyl acetate)

Sources & evidence

ORD record
ord-55141c490cca4d09a9bf4a1b16d8021a
Source dataset
uspto-grants-1991_04
Patent number
US05010102

Reaction notes

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