Phosphorus oxychloride → 5-Bromo-4-chloro-1H-pyrrolo(2,3-b)pyridine

HRID 1693692Notes

Reaction equation

HRID 1693692 reaction equation
[Br:1][C:2]1[CH:3]=[C:4]2[CH:11]=[CH:10][NH:9][C:5]2=[N+:6]([O-])[CH:7]=1.P(Cl)(Cl)([Cl:14])=O>CN1C(=O)CCC1>[Br:1][C:2]1[C:3]([Cl:14])=[C:4]2[CH:11]=[CH:10][NH:9][C:5]2=[N:6][CH:7]=1

Participants

4

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 178526231HCID 178526231, compound

Product 1

HCID 457897885-Bromo-4-chloro-1H-pyrrolo(2,3-b)pyridineYield 48%

Reagents, catalysts & solvents 1

HCID 13387N-methyl-2-pyrrolidoneSolvent

Conditions

Temperature
-20 °C

Procedure

5-Bromo-1H-pyrrolo[2,3-b]pyridine 7-oxide (19.18 g, 90 mmol) were suspended in 200 mL NMP and cooled to −20° C. Phosphorus oxychloride (41 mL, 450 mmol) was added dropwise over 30 min. The mixture was allowed to warm to 23° C. over 1 h after which it was cooled on an ice bath and quenched with water (800 mL). The solids were filtered and recrystallized from ethyl acetate and hexanes to give 5-Bromo-4-chloro-1H-pyrrolo[2,3-b]pyridine (10 g, 48%). 1H NMR (500 MHz, DMSO-d6) δ 12.25 (bs, 1H), 8.4 (s, 1H), 7.65 (m, 1H), 6.52 (m, 1H). MS: m/z 230.8/232.8 (M+H+).

Workup

  1. temperatureto warm to 23° C. over 1 h after which it
  2. temperaturewas cooled on an ice bath
  3. customquenched with water (800 mL)
  4. filtrationThe solids were filtered
  5. customrecrystallized from ethyl acetate and hexanes

Sources & evidence

ORD record
ord-0197c0c0b3b341c4bc7d0f3f12b08353
Source dataset
uspto-grants-2012_04
Patent number
US08158647B2

Reaction notes

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