Réaction #531830

Équation de réaction

methanesulfonyl chloride

3-chloro-1-(3-chloro-2-pyridinyl)-1H-pyrazole-5-carboxylic acid

carboxylic acid

3-chloro-1-(3-chloro-2-pyridinyl)-1H-pyrazole-5-carboxylic acid

triethylamine

2-amino-3-chloro-5-iodobenzoic acid

triethylamine

methanesulfonyl chloride

→

title compound

8-chloro-2-[3-chloro-1-(3-chloro-2-pyridinyl)-1H-pyrazol-5-yl]-6-iodo-4H-3,1-benzoxazin-4-one

Solvants

acetonitrile

acetonitrile

water

acetonitrile

Conditions de réaction

Traitement

1. 1
   workup.STIRRINGstirring
2. 2
   workup.WAITwas continued for an additional 5 minutes
3. 3
   Autrethe temperature below 5° C
4. 4
   workup.STIRRINGThe reaction mixture was stirred 40 minutes at 0° C.
5. 5
   TempératureThe reaction mixture was then warmed to room temperature
6. 6
   workup.STIRRINGstirred overnight
7. 7
   Extractionextracted with ethyl acetate (3×50 mL)
8. 8
   LavageThe combined ethyl acetate extracts were washed successively with 10% aqueous sodium bicarbonate (1×20 mL) and brine (1×20 mL)
9. 9
   Séchagedried (MgSO4)
10. 10
    Concentrationconcentrated under reduced pressure
11. 11
    AutreThe residual solid was purified by chromatography on silica gel

Mode opératoire

To a solution of methanesulfonyl chloride (0.31 mL, 4.07 mmol) in acetonitrile (10 mL) was added dropwise a mixture of 3-chloro-1-(3-chloro-2-pyridinyl)-1H-pyrazole-5-carboxylic acid (i.e. the carboxylic acid product of Example 3, Step D) (1.0 g, 3.87 mmol) and triethylamine (0.54 mL, 3.87 mmol) in acetonitrile (5 mL) at 0° C. The reaction mixture was then stirred for 15 minutes at 0° C. Then, 2-amino-3-chloro-5-iodobenzoic acid (i.e. the product from Step A) (1.15 g, 3.87 mmol) was added, and stirring was continued for an additional 5 minutes. A solution of triethylamine (1.08 mL, 7.74 mmol) in acetonitrile (5 mL) was then added dropwise while keeping the temperature below 5° C. The reaction mixture was stirred 40 minutes at 0° C., and then methanesulfonyl chloride (0.31 mL, 4.07 mmol) was added. The reaction mixture was then warmed to room temperature and stirred overnight. The reaction mixture was then diluted with water (50 mL) and extracted with ethyl acetate (3×50 mL). The combined ethyl acetate extracts were washed successively with 10% aqueous sodium bicarbonate (1×20 mL) and brine (1×20 mL), dried (MgSO4) and concentrated under reduced pressure. The residual solid was purified by chromatography on silica gel to afford 575 mg of the title compound as a crude yellow solid.

Source