Dichloromethane → 3-Methoxy-2-methylbenzohydrazide

HRID 968939Notes

Reaction equation

HRID 968939 reaction equation
[C:1]([O-:4])([O-])=O.[K+].[K+].[OH2:7].[NH2:8][NH2:9].CO[C:12]1[CH:13]=[C:14]([CH:18]=[CH:19][CH:20]=1)[C:15](Cl)=O.[CH2:21](Cl)Cl>O.C(Cl)(Cl)Cl>[CH3:21][O:7][C:13]1[C:14]([CH3:15])=[C:18]([CH:19]=[CH:20][CH:12]=1)[C:1]([NH:8][NH2:9])=[O:4]

Participants

7

Reactant 4

HCID 6344Dichloromethane3×HCID 11430Potassium CarbonateHCID 24654Hydrazine hydrate (1:1)HCID 74374m-Anisoyl chloride

Product 1

HCID 450912733-Methoxy-2-methylbenzohydrazide

Reagents, catalysts & solvents 2

HCID 962WaterSolvent2×HCID 6212ChloroformSolvent

Procedure

To a 500 mL, 3-neck flask equipped with magnetic stirring, and chilled in an ice water bath, were added 50 mL CH2Cl2, followed by a solution of 32 g (231 mmol) K2CO3 dissolved in 80 mL water, and 24 g (479 mmol) hydrazine hydrate. Over a period of 30–60 minutes, a solution of 20 g (108.3 mmol) 2-methyl, 3-methoxybenzoyl chloride dissolved in 100 mL CH2Cl2 were added, while keeping the temperature below 10° C. The reaction mixture was stirred for an additional hour, during which time a precipitate formed. The precipitate was collected and shaken with a CH2Cl2/CHCl3 mixture; the liquid phase was separated from remaining solids, and solvent was removed in vacuo to leave 5.85 g crude product hydrazide. Meanwhile, the original CH2Cl2 solution was transferred to a separatory funnel, diluted with CHCl3, and shaken with water. The organic layer was removed, washed again with water, dried, and solvent was evaporated to leave a solid residue. This was washed thoroughly with hexane and filtered to provide an additional 6.05 g crude product hydrazide. The combined crude hydrazide was recrystallized from hot ether or ethyl acetate/hexane mixtures to yield 10.04 g 3-methoxy-2-methyl-benzoic acid hydrazide: 1H NMR (300 MHz, CDCl3) δ (ppm): 7.2 (t, 1H), 6.95 (br s, 1H), 6.9 (m, 2H), 4.15 (br s, 2H), 3.84 (s, 3H), 2.27 (s, 3H).

Workup

  1. customTo a 500 mL, 3-neck flask equipped with magnetic stirring
  2. temperaturechilled in an ice water bath
  3. waitOver a period of 30–60 minutes
  4. additionwere added
  5. customthe temperature below 10° C
  6. customformed
  7. customThe precipitate was collected
  8. stirringshaken with a CH2Cl2/CHCl3 mixture
  9. customthe liquid phase was separated
  10. customwas removed in vacuo
  11. customto leave 5.85 g crude product hydrazide
  12. customThe organic layer was removed
  13. washwashed again with water
  14. customdried
  15. customsolvent was evaporated
  16. customto leave a solid residue
  17. washThis was washed thoroughly with hexane
  18. filtrationfiltered
  19. customto provide an additional 6.05 g crude product hydrazide
  20. customwas recrystallized from hot ether or ethyl acetate/hexane

Sources & evidence

ORD record
ord-dd12d0e368754613b0376d899c248e46
Source dataset
uspto-grants-2007_12
Patent number
US07304161B2

Reaction notes

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