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

HRID 434864

反応式

HRID 434864 の反応式
[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]

参加物

5

実験手順

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 115-140 were combined and evaporated to dryness to yield the undesired Rf 0.35 isomer (860 mg., m.p. 86°-88° C.). Fractions 240-310 were combined to yield the desired 3-chloro-6-methoxy-2-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)].

後処理

  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
  12. customevaporated to dryness
  13. customto yield the undesired Rf 0.35 isomer (860 mg., m.p. 86°-88° C.)

出典と根拠

ORDレコード
ord-38cfb366a5fb4feb9c66e8d7739934b3
出典データセット
uspto-grants-1983_08
特許番号
US04399296

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