tert-Butyl methyl ether → 3-Fluoro-4'-pentyl-4-(trifluoromethoxy)biphenyl-2-carbaldehyde

HRID 1839900Notes

Reaction equation

HRID 1839900 reaction equation
Br[C:2]1[CH:9]=[CH:8][C:7]([O:10][C:11]([F:14])([F:13])[F:12])=[C:6]([F:15])[C:3]=1[CH:4]=[O:5].[CH2:16]([C:21]1[CH:26]=[CH:25][C:24](OB(O)O)=[CH:23][CH:22]=1)[CH2:17][CH2:18][CH2:19][CH3:20].[F-].[Cs+].COC(C)(C)C>C(COC)OC.C1C=CC([P]([Pd]([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)[P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1.O>[F:15][C:6]1[C:7]([O:10][C:11]([F:14])([F:13])[F:12])=[CH:8][CH:9]=[C:2]([C:24]2[CH:23]=[CH:22][C:21]([CH2:16][CH2:17][CH2:18][CH2:19][CH3:20])=[CH:26][CH:25]=2)[C:3]=1[CH:4]=[O:5]

Participants

8

Reactant 4

HCID 15413tert-Butyl methyl etherHCID 25953Cesium fluorideHCID 102148076-Bromo-2-fluoro-3-(trifluoromethoxy)benzaldehydeHCID 234509174-Pentylphenylboric acid

Product 1

HCID 234509163-Fluoro-4'-pentyl-4-(trifluoromethoxy)biphenyl-2-carbaldehyde

Reagents, catalysts & solvents 3

HCID 178418397HCID 178418397, compoundCatalystHCID 962WaterSolventHCID 80711,2-DimethoxyethaneSolvent

Procedure

A mixture of 98 mmol of 2-bromo-6-fluoro-5-trifluoromethoxybenzaldehyde (Example 1), 112 mmol of 4-pentylphenylboric acid, 225 mmol of cesium fluoride (anhydrous) and 3.4 mmol of tetrakis(triphenylphosphine)palladium(0) in 480 ml of dimethoxyethane is heated to boiling until the reaction is complete. After cooling, the reaction mixture is admixed with tert-butyl methyl ether and water. The organic phase is washed with water and saturated NaCl solution and dried over sodium sulfate, and the solvents are removed under reduced pressure. After chromatographic purification of the crude product (silica gel, heptane/ethyl acetate 9:1), followed by recrystallization from heptane, 3-fluoro-4′-pentyl-4-(trifluoromethoxy)biphenyl-2-carbaldehyde is obtained in the form of colorless crystals. From this, the reaction sequence described in DE-A-101 01 020 (oxidation to the carboxylic acid, conversion to the acid chloride, intramolecular Friedel-Crafts reaction, reduction with triethylsilane) provides 1-fluoro-7-pentyl-2-(trifluoromethoxy)fluorene which, according to DE-A-101 01 020, finds use as a component of nematic or smectic liquid crystal mixtures.

Workup

  1. temperatureis heated
  2. temperatureAfter cooling
  3. washThe organic phase is washed with water and saturated NaCl solution
  4. dry with materialdried over sodium sulfate
  5. customthe solvents are removed under reduced pressure
  6. customAfter chromatographic purification of the crude product (silica gel, heptane/ethyl acetate 9:1)
  7. customfollowed by recrystallization from heptane

Sources & evidence

ORD record
ord-c8ef4516a3d0402ab76fe6ced6ac2f77
Source dataset
uspto-grants-2004_01
Patent number
US06677479B2

Reaction notes

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