Hydrochloric Acid → 6-Fluoro-3-pentylchroman-7-carbaldehyde

HRID 2420646Notes

Reaction equation

HRID 2420646 reaction equation
Br[C:2]1[CH:11]=[C:10]2[C:5]([CH2:6][CH:7]([CH2:12][CH2:13][CH2:14][CH2:15][CH3:16])[CH2:8][O:9]2)=[CH:4][C:3]=1[F:17].C([Li])CCC.[CH:23](N1CCCCC1)=[O:24].Cl>C1COCC1.CCCCCC.O>[F:17][C:3]1[CH:4]=[C:5]2[C:10](=[CH:11][C:2]=1[CH:23]=[O:24])[O:9][CH2:8][CH:7]([CH2:12][CH2:13][CH2:14][CH2:15][CH3:16])[CH2:6]2

Participants

8

Reactant 4

HCID 313Hydrochloric AcidHCID 174291-PiperidinecarboxaldehydeHCID 592883377-Bromo-6-fluoro-3-pentylchromanHCID 178418339Butyllithium

Product 1

HCID 592883516-Fluoro-3-pentylchroman-7-carbaldehyde

Reagents, catalysts & solvents 3

HCID 962WaterSolventHCID 8028TetrahydrofuranSolvent2×HCID 8058HexaneSolvent

Procedure

15.5 g (51.5 mmol) of 7-bromo-6-fluoro-3-pentylchroman are dissolved in 85 ml of THF, and 35 ml (55.7 mmol) of a 15 percent solution of n-butyllithium in n-hexane are slowly added at −70° C. After 1 h, 6.3 ml (56.7 mmol) of N-formylpiperidine in 15 ml of THF are added dropwise, and the mixture is stirred for 1 h. The batch is subsequently allowed to thaw, added to water, acidified using dil. hydrochloric acid and extracted three times with MTB ether. The combined org. phases are washed with water and sat. sodium chloride soln. and dried over sodium sulfate, the solvent is removed in vacuo, and the residue is recrystallised from heptane at −25° C., giving 6-fluoro-3-pentylchroman-7-carbaldehyde as colourless crystals (Rf=0.4; 1-chlorobutane).

Workup

  1. extractionextracted three times with MTB ether
  2. washphases are washed with water and sat. sodium chloride soln
  3. dry with materialand dried over sodium sulfate
  4. customthe solvent is removed in vacuo
  5. customthe residue is recrystallised from heptane at −25° C.

Sources & evidence

ORD record
ord-63485a51519049168b72d9ac649dbebd
Source dataset
uspto-grants-2011_06
Patent number
US07955664B2

Reaction notes

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