Phosphorus oxychloride → 4-Chloro-2-methyl-10-(2,4,6-trimethylphenyl)pyrido[2,3-b]indolizine

HRID 636820Notes

Reaction equation

HRID 636820 reaction equation
O[C:2]1[C:14]2[N:13]3[C:8]([CH:9]=[CH:10][CH:11]=[CH:12]3)=[C:7]([C:15]3[C:20]([CH3:21])=[CH:19][C:18]([CH3:22])=[CH:17][C:16]=3[CH3:23])[C:6]=2[N:5]=[C:4]([CH3:24])[CH:3]=1.P(Cl)(Cl)([Cl:27])=O>>[Cl:27][C:2]1[C:14]2[N:13]3[C:8]([CH:9]=[CH:10][CH:11]=[CH:12]3)=[C:7]([C:15]3[C:20]([CH3:21])=[CH:19][C:18]([CH3:22])=[CH:17][C:16]=3[CH3:23])[C:6]=2[N:5]=[C:4]([CH3:24])[CH:3]=1

Participants

3

Procedure

A solution of 4-hydroxy-2-methyl-10-(2,4,6-trimethylphenyl)pyrido-[2,3-b]indolizine (10.1 g; 32 mmol) in phosphorus oxychloride (60 mL) is heated at 100° C. for 1 hour, cooled to room temperature, and concentrated in vacuo. The residue is partitioned into ice water and dichloromethane. The aqueous phase is separated and extracted twice with dichloromethane. The combined organics are washed with a 1 N aqueous sodium hydroxide solution and then with water. The solution is dried (Na2SO4), filtered, and concentrated in vacuo, and the resulting dark residue is filtered through a short pad of silica gel and washed with 25% ethyl acetate in hexane. The filtrate is concentrated in vacuo to give 10.1 g of the title compound as a yellow solid (94%): 1H nmr (400 MHz, CDCl3) d 2.00 (s, 6 H), 2.37 (s, 3 H), 2.64 (s, 3 H), 6.58 (t, 1 H), 6.95 (dd, 1 H), 7.00 (s, 2 H), 7.07 (s, 1 H), 7.08 (d, 1 H), 9.26 (d, 1 H).

Workup

  1. concentrationconcentrated in vacuo
  2. customThe residue is partitioned into ice water and dichloromethane
  3. customThe aqueous phase is separated
  4. extractionextracted twice with dichloromethane
  5. washThe combined organics are washed with a 1 N aqueous sodium hydroxide solution
  6. dry with materialThe solution is dried (Na2SO4)
  7. filtrationfiltered
  8. concentrationconcentrated in vacuo
  9. filtrationthe resulting dark residue is filtered through a short pad of silica gel
  10. washwashed with 25% ethyl acetate in hexane
  11. concentrationThe filtrate is concentrated in vacuo

Sources & evidence

ORD record
ord-261bcda3b81d4731a71b1e64047cbe6b
Source dataset
uspto-grants-2001_02
Patent number
US06194574B1

Reaction notes

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