Methane, dichloromethoxy- → 3-Chloro-6-methoxy-2-methylbenzaldehyde

HRID 544336

Reaction equation

HRID 544336 reaction equation
[Cl:1][C:2]1[CH:7]=[CH:6][C:5]([O:8][CH3:9])=[CH:4][C:3]=1[CH3:10].[CH3:11][O:12]C(Cl)Cl>[Ti](Cl)(Cl)(Cl)Cl.C(Cl)Cl>[Cl:1][C:2]1[C:3]([CH3:10])=[C:4]([C:5]([O:8][CH3:9])=[CH:6][CH:7]=1)[CH:11]=[O:12]

Participants

5

Reactant 2

HCID 21004Methane, dichloromethoxy-HCID 4581561-Chloro-4-methoxy-2-methylbenzene

Product 1

HCID 130935613-Chloro-6-methoxy-2-methylbenzaldehyde

Reagents, catalysts & solvents 2

HCID 24193Titanium TetrachlorideCatalystHCID 6344DichloromethaneSolvent

Procedure

4-Chloro-3-methylanisole (15.4 g., 0.10 mole) was taken into 200 ml. of methylene chloride and cooled to 0° C. Titanium tetrachloride (37.9 g., 0.2 mole) and then 1,1-dichloromethyl methyl ether (13.8 g., 0.12 mole) were added, each over a 2 minute period. The reaction mixture was stirred at room temperature for 1 hour, poured over 500 ml. of ice and water and the organic layer separated. The aqueous layer was extracted with two portions of fresh methylene chloride and these extracts combined with the original organic layer. The combined organic layers were washed with brine, dried over anhydrous magnesium sulfate, filtered and concentrated dryness (15.2 g., 82%), containing two thirds 5-chloro-2-methoxy-4-methylbenzaldehyde [Rf 0.35 (1:1 chloroform:hexane] and one third of the desired isomeric product [Rf 0.28 (1:1 chloroform:hexane]. These two compounds were separated by chromatography on 1 kg. of silica gel, eluting with 1:1 methylene chloride:hexane, collecting 15 ml. fractions and monitoring by tlc. Fractions-methylbenzaldehyde [1.61 g.; m.p. 95°-97° C., pnmr/ CDCl3 /delta 2.4 (s, 3H), 3.9 (s, 3H), 6.8 (s, 1H), 7.7 (s, 1H), 10.4 (s, 1H); Rf 0.28 (1:1 methylene chloride: hexane)].

Workup

  1. additionpoured over 500 ml
  2. customof ice and water and the organic layer separated
  3. extractionThe aqueous layer was extracted with two portions of fresh methylene chloride
  4. washThe combined organic layers were washed with brine
  5. dry with materialdried over anhydrous magnesium sulfate
  6. filtrationfiltered
  7. concentrationconcentrated dryness (15.2 g., 82%)
  8. additioncontaining two thirds 5-chloro-2-methoxy-4-methylbenzaldehyde [Rf 0.35 (1:1 chloroform
  9. customThese two compounds were separated by chromatography on 1 kg
  10. washof silica gel, eluting with 1:1 methylene chloride
  11. customhexane, collecting 15 ml

Sources & evidence

ORD record
ord-483e1573c5034eaab2aa4473a724c762
Source dataset
uspto-grants-1984_05
Patent number
US04448971

Linked notes

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