Benzaldehyde → (3E)-6-Fluoro-2,3-dihydro-3-(phenylmethylene)-4H-1-benzopyran-4-one

HRID 736450Notes

Reaction equation

HRID 736450 reaction equation
[F:1][C:2]1[CH:3]=[C:4]2[C:9](=[CH:10][CH:11]=1)[O:8][CH2:7][CH2:6][C:5]2=[O:12].[CH:13](=O)[C:14]1[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=1>CCO>[CH:13](=[C:6]1/[CH2:7][O:8][C:9]2[C:4]([C:5]/1=[O:12])=[CH:3][C:2]([F:1])=[CH:11][CH:10]=2)/[C:14]1[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=1

Participants

4

Reactant 2

HCID 240BenzaldehydeHCID 27332626-fluoro-2,3-dihydro-4H-1-benzopyran-4-one

Product 1

HCID 57849017(3E)-6-Fluoro-2,3-dihydro-3-(phenylmethylene)-4H-1-benzopyran-4-one

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

6-Fluoro-4-chromanone (5.0 g, 30.1 mmol) and 3.35 g (31.6 mmol) benzaldehyde were dissolved in 100 mL of EtOH, and HCl gas was bubbled through the solution until it was nearly boiling. The flask was then capped, allowed to cool to room temperature and stirred overnight. The solids were filtered off and rinsed with a minimum amount of Et2O to provide 1-1 as a light-pinkish solid. Data for 1-1: 1HNMR (500 MHz, CDCl3) δ 7.9 (s, 1H), 7.65 (m, 1H), 7.5-7.4 (m, 3H), 7.3 (m, 2H), 7.2 (m, 1H), 6.95 (m, 1H), 5.35 (s, 2H) ppm. LC-MS: rt=2.8 min, m/z=255 (M+1).

Workup

  1. customHCl gas was bubbled through the solution until it
  2. customThe flask was then capped
  3. filtrationThe solids were filtered off
  4. washrinsed with a minimum amount of Et2O

Sources & evidence

ORD record
ord-6a34acb47c7248e7a3cc195de8e41cf3
Source dataset
uspto-grants-2009_09
Patent number
US07595337B2

Reaction notes

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