Methyl acetoacetate → 1-Methyl-1,3,4,9-tetrahydroindeno[2,1-c]pyran-1-acetic acid methyl ester

HRID 1731135Notes

Reaction equation

HRID 1731135 reaction equation
[CH2:1]1[C:9]2[C:4](=[CH:5][CH:6]=[CH:7][CH:8]=2)[C:3]([CH2:10][CH2:11][OH:12])=[CH:2]1.[C:13]([O:19][CH3:20])(=[O:18])[CH2:14][C:15]([CH3:17])=O.B(F)(F)F.CCOCC>C1C=CC=CC=1>[CH3:20][O:19][C:13](=[O:18])[CH2:14][C:15]1([CH3:17])[C:2]2[CH2:1][C:9]3[CH:8]=[CH:7][CH:6]=[CH:5][C:4]=3[C:3]=2[CH2:10][CH2:11][O:12]1

Participants

5

Reactant 3

HCID 7757Methyl acetoacetateHCID 8000Boron trifluoride etherate2×HCID 113556481H-Indene-3-ethanol

Product 1

HCID 536402551-Methyl-1,3,4,9-tetrahydroindeno[2,1-c]pyran-1-acetic acid methyl ester

Reagents, catalysts & solvents 1

HCID 241BenzeneSolvent

Procedure

To a solution of indene-3-ethanol (8 g) and methyl acetoacetate (6 g) in 250 ml of dry benzene containing hydrated alkali-aluminum silicate (Molecular Sieves No. 4, about 2 g) is added 1 ml of boron trifluoride-etherate and the mixture stirred at room temperature for 4 hr. An additional 1 ml of boron trifluoride-etherate is added, the reaction mixture is stirred at ambient temperature overnight and then heated at reflux for 1 hr. The hydrated alkali-aluminum silicate is collected and the filtrate washed with 10% solution of sodium bicarbonate and water. After drying over magnesium sulfate the benzene is removed under reduced pressure affording 1-methyl-1,3,4,9-tetrahydroindeno[2,1-c]pyran-1-acetic acid methyl ester, νmaxfilm 1724 cm-1.

Workup

  1. stirringthe reaction mixture is stirred at ambient temperature overnight
  2. temperatureheated
  3. temperatureat reflux for 1 hr
  4. customThe hydrated alkali-aluminum silicate is collected
  5. washthe filtrate washed with 10% solution of sodium bicarbonate and water
  6. dry with materialAfter drying over magnesium sulfate the benzene
  7. customis removed under reduced pressure

Sources & evidence

ORD record
ord-686e3559f0cb419caf978999feecb49b
Source dataset
uspto-grants-1976_11
Patent number
US03995052

Reaction notes

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