Pyrazole → Benzoic acid, 4-(3-chloropropoxy)-3-methoxy-

HRID 1899139Notes

Reaction equation

HRID 1899139 reaction equation
[H-].[Na+].CC[O:5]CC.N1C=CC=N1.[Cl:13][CH2:14][CH2:15][CH2:16][O:17][C:18]1[CH:25]=[CH:24][C:21]([CH:22]=[O:23])=[CH:20][C:19]=1[O:26][CH3:27]>O1CCCC1>[Cl:13][CH2:14][CH2:15][CH2:16][O:17][C:18]1[CH:25]=[CH:24][C:21]([C:22]([OH:5])=[O:23])=[CH:20][C:19]=1[O:26][CH3:27]

Participants

6

Reactant 4

HCID 1048PyrazoleHCID 3283Diethyl EtherHCID 24758Sodium hydrideHCID 46108414-(3-Chloropropoxy)-M-anisaldehyde

Product 1

HCID 10354496Benzoic acid, 4-(3-chloropropoxy)-3-methoxy-

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Procedure

To a stirred suspension under nitrogen of sodium hydride (6.4 g, 130 mmol, of about 50% oil dispersion-ether washed) in tetrahydrofuran (220 ml) was added pyrazole (4.4 g, 60 mmol) in tetrahydrofuran (60 ml), dropwise. After complete addition, the reaction was stirred for about 15 minutes, and then 4-(3-chloropropoxy)-3-methoxybenzaldehyde (24.5 g, 107 mmol) was added. The nitrogen was stopped and air was sparged into the reactor for about 3 hours. The reaction was then allowed to stir at ambient temperature open to the atmosphere for 6 hours. Water was added, the reaction was cooled in an ice bath, and concentrated hydrochloric acid (25 ml) was added dropwise. More water was added and the yellow solid that separated was collected to afford 16.2 g of product. The filtrate was then extracted with ethyl acetate to afford an additional 9.3 g. The samples were combined and recrystallized from acetonitrile to yield 12.6 g of a light, yellow solid, m.p.=154°-156° C. A 4.0 g sample was recrystallized from acetonitrile to yield 2.6 g of a yellow solid. This was combined with 0.4 g from another sample and recrystallized again from acetonitrile with charcoal treatment to afford 2.0 g of 4-(3-chloropropoxy)-4-methoxybenzoic acid as a yellow solid, m.p.=157°-159° C.

Workup

  1. additionAfter complete addition
  2. customair was sparged into the reactor for about 3 hours
  3. stirringto stir at ambient temperature open to the atmosphere for 6 hours
  4. additionWater was added
  5. temperaturethe reaction was cooled in an ice bath
  6. additionconcentrated hydrochloric acid (25 ml) was added dropwise
  7. additionMore water was added
  8. customthe yellow solid that separated
  9. customwas collected

Sources & evidence

ORD record
ord-a7c78f575b334b209033c4a85147be9b
Source dataset
uspto-grants-1996_11
Patent number
US05571814

Reaction notes

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