Phosphorus oxychloride → methyl 2-chloro-1H-1,3-benzodiazole-7-carboxylate

HRID 1505793Notes

Reaction equation

HRID 1505793 reaction equation
O=[C:2]1[NH:6][C:5]2[CH:7]=[CH:8][CH:9]=[C:10]([C:11]([O:13][CH3:14])=[O:12])[C:4]=2[NH:3]1.P(Cl)(Cl)([Cl:17])=O>>[Cl:17][C:2]1[NH:6][C:5]2[CH:7]=[CH:8][CH:9]=[C:10]([C:11]([O:13][CH3:14])=[O:12])[C:4]=2[N:3]=1

Participants

3

Reactant 2

HCID 24813Phosphorus oxychlorideHCID 22745204HCID 22745204, compound

Product 1

HCID 68407476methyl 2-chloro-1H-1,3-benzodiazole-7-carboxylate

Conditions

Temperature
120 °C

Procedure

A solution of methyl 2-oxo-2,3-dihydro-1H-benzimidazole-4-carboxylate (prepared as described in US2009/186879) (2.0 g) in phosphoryl chloride (18 mL) was stirred at 120° C. for 2.5 hours. Excessive phosphoryl chloride was removed under reduced pressure. To the residue was added saturated aqueous sodium bicarbonate under ice-cooling, and it was extracted with ethyl acetate. The ethyl acetate layer was dried over anhydrous magnesium sulfate and concentrated. The residue was purified on column chromatography to obtain the titled compound (1.5 g) as white powder.

Workup

  1. customExcessive phosphoryl chloride was removed under reduced pressure
  2. additionTo the residue was added saturated aqueous sodium bicarbonate under ice-
  3. temperaturecooling
  4. extractionit was extracted with ethyl acetate
  5. dry with materialThe ethyl acetate layer was dried over anhydrous magnesium sulfate
  6. concentrationconcentrated
  7. customThe residue was purified on column chromatography

Sources & evidence

ORD record
ord-59bb7b8c8ada4687a64bb879afddaffd
Source dataset
uspto-grants-2015_12
Patent number
US09216968B2

Reaction notes

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