Formaldehyde → 6-bromo-2-methylene-2,3-dihydro-1H-inden-1-one

HRID 2168311Notes

Reaction equation

HRID 2168311 reaction equation
[Br:1][C:2]1[CH:10]=[C:9]2[C:5]([CH2:6][CH2:7][C:8]2=[O:11])=[CH:4][CH:3]=1.C=O.[C:14]1(B(O)O)C=CC=CC=1.FC(F)(F)C(O)=O>C1(C)C=CC=CC=1>[Br:1][C:2]1[CH:10]=[C:9]2[C:5]([CH2:6][C:7](=[CH2:14])[C:8]2=[O:11])=[CH:4][CH:3]=1

Participants

6

Reactant 4

HCID 712FormaldehydeHCID 6422Trifluoroacetic acidHCID 66827Phenylboronic AcidHCID 1397781-Indanone, 6-bromo-

Product 1

HCID 581971666-bromo-2-methylene-2,3-dihydro-1H-inden-1-oneYield 30%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

A solution of 6-bromo-2,3-dihydro-1H-inden-1-one (0.3 g, 1.36 mmol), paraformaldehyde (0.4 g, 13.6 mmol), phenylboronic acid (0.2 g, 1.64 mmol) and trifluoroacetic acid (0.1 mL, 0.15 g, 1.36 mmol) in dry toluene (10 mL) was refluxed for 5 hours. When starting material was totally consumed, the crude mixture was cooled to room temperature, neutralized with saturated aqueous Na2CO3, extracted with ethyl acetate, dried and concentrated under reduced pressure. The residue was purified by flash column chromatography (silica gel, petroleum ether-ethyl acetate, 95:5) to give compound 6-bromo-2-methylene-2,3-dihydro-1H-inden-1-one (89 mg, 30%) as a white solid. 1H NMR (CDCl3, 400 MHz): 3.71 (s, 2H), 5.68 (s, 1H), 6.39 (s, 1H), 7.38-7.40 (d, 1H), 7.70-7.72 (d, 1H), 7.99 (s, 1H).

Workup

  1. customwas totally consumed
  2. extractionextracted with ethyl acetate
  3. customdried
  4. concentrationconcentrated under reduced pressure
  5. customThe residue was purified by flash column chromatography (silica gel, petroleum ether-ethyl acetate, 95:5)

Sources & evidence

ORD record
ord-4263e9ef95164dd0930c99abca3b5606
Source dataset
uspto-grants-2015_06
Patent number
US09045500B2

Reaction notes

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