Hydrochloric Acid → Pyrithiobac

HRID 1885979Notes

Reaction equation

HRID 1885979 reaction equation
[Cl:1][C:2]1[C:7]([C:8]([OH:10])=[O:9])=[C:6]([SH:11])[CH:5]=[CH:4][CH:3]=1.[H-].[Na+].[CH3:14][O:15][C:16]1[CH:21]=[C:20]([O:22][CH3:23])[N:19]=[C:18](S(C)(=O)=O)[N:17]=1.[Cl-].[Na+].Cl>CN(C)C=O.C(OCC)(=O)C.O>[Cl:1][C:2]1[C:7]([C:8]([OH:10])=[O:9])=[C:6]([S:11][C:18]2[N:19]=[C:20]([O:22][CH3:23])[CH:21]=[C:16]([O:15][CH3:14])[N:17]=2)[CH:5]=[CH:4][CH:3]=1

Participants

9

Reactant 5

HCID 313Hydrochloric AcidHCID 5234Sodium ChlorideHCID 24758Sodium hydrideHCID 8383634,6-Dimethoxy-2-(methylsulfonyl)pyrimidineHCID 144382762-Chloro-6-sulfanylbenzoic acid

Product 1

HCID 91781Pyrithiobac

Reagents, catalysts & solvents 3

HCID 962WaterSolventHCID 6228DimethylformamideSolventHCID 8857Ethyl AcetateSolvent

Procedure

A solution of 1.4 grams (0.007 mole) of 6-chloro-2-mercaptobenzoic acid in 50 mL of dimethylformamide was stirred, and 0.6 gram (0.01 mole) of 60% sodium hydride in mineral oil was added in two portions during a 3 minute period. After this time the reaction mixture was stirred for 30 minutes, and 1.6 grams (0.007 mole) of 4,6-dimethoxy-2-methylsulfonylpyrimidine (prepared as in Example 1, Steps A-C) was added. Upon completion of addition, the reaction mixture was stirred for about 60 hours. After this time the reaction mixture was poured into 150 mL of an aqueous solution saturated with sodium chloride. Water, 50 mL, was added, and the mixture was extracted with three 70 mL portions of ethyl acetate. The combined extracts were evaporated under reduced pressure, leaving no residue. The aqueous layer was cooled and acidified to pH 2 with aqueous 3N hydrochloric acid. The mixture was reextracted with three 70 mL portions of ethyl acetate. The combined extracts were washed with four 50 mL portions of an aqueous solution saturated with sodium chloride. The organic layer was concentrated under reduced pressure to a residue. The residue was subjected to two purifications by column chromatography on silica gel. Elution for the first purification was accomplished using 10% methanol in methylene chloride, and with 33% acetone in methylene chloride for the second purification. The yield of 6-chloro-2-(4,6-dimethoxypyrimidin-2-ylthio)benzoic acid was 0.3 gram. The nmr spectrum was consistent with the proposed structure.

Workup

  1. additionUpon completion of addition
  2. stirringthe reaction mixture was stirred for about 60 hours
  3. extractionthe mixture was extracted with three 70 mL portions of ethyl acetate
  4. customThe combined extracts were evaporated under reduced pressure
  5. customleaving no residue
  6. temperatureThe aqueous layer was cooled
  7. washThe combined extracts were washed with four 50 mL portions of an aqueous solution saturated with sodium chloride
  8. concentrationThe organic layer was concentrated under reduced pressure to a residue
  9. washElution
  10. customfor the first purification
  11. customwith 33% acetone in methylene chloride for the second purification

Sources & evidence

ORD record
ord-afa72af727b34035813d19df2fa38fe1
Source dataset
uspto-grants-1992_09
Patent number
US05149357

Reaction notes

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