Tetrahydrofuran → Methyl 2-methyl-5-benzothiazolecarboxylate

HRID 501801Notes

Reaction equation

HRID 501801 reaction equation
[OH-].[Na+].[CH3:3][C:4]1[S:5][C:6]2[CH:12]=[CH:11][C:10]([CH:13]=[O:14])=[CH:9][C:7]=2[N:8]=1.[O:15]1CCC[CH2:16]1>O.[N+]([O-])([O-])=O.[Ag+]>[CH3:3][C:4]1[S:5][C:6]2[CH:12]=[CH:11][C:10]([C:13]([O:15][CH3:16])=[O:14])=[CH:9][C:7]=2[N:8]=1

Participants

6

Reactant 3

HCID 8028TetrahydrofuranHCID 14798Sodium HydroxideHCID 23088202-Methylbenzo[d]thiazole-5-carbaldehyde

Product 1

HCID 10910723Methyl 2-methyl-5-benzothiazolecarboxylate

Reagents, catalysts & solvents 2

HCID 24470Silver NitrateCatalystHCID 962WaterSolvent2×

Procedure

3.83 g of silver nitrate was dissolved in 10 mL of water, to which a solution of 1.81 g of sodium hydroxide in 10 mL of water was added dropwise and then a solution of 2.00 g of 2-methyl-1,3-benzothiazole-5-carbaldehyde in 20 mL of tetrahydrofuran was added dropwise at room temperature, and this solution was stirred for 30 minutes at the same temperature. The reaction mixture was filtered through Celite, and 6M hydrochloric acid was added to the filtrate to adjust its pH value to 3.5 followed by addition of ethyl acetate, and then the organic phase was separated therefrom. After the resultant organic phase was washed with a saturated sodium chloride solution, the washed phase was dried over anhydrous magnesium sulfate, and the solvent was distilled out under reduced pressure. The resultant residue was dissolved in 30 mL of methylene chloride, to which 20 μL of N,N-dimethylformamide and 1.5 mL of oxalyl chloride were added successively, and this solution was stirred for 30 minutes at room temperature. The reaction mixture, to which 20 mL of methanol was added dropwise, was stirred for 30 minutes at room temperature, and after water was added thereto, the pH value of this mixture was adjusted to 7 with a 5M solution of sodium hydroxide in water, and then the organic phase was separated therefrom. After the resultant organic phase was washed with a saturated sodium chloride solution, the washed phase was dried over anhydrous magnesium sulfate, and the solvent was distilled out under reduced pressure to yield 1.90 g of methyl 2-methyl-1,3-benzothiazole-5-carboxylate as light yellow solid.

Workup

  1. additionwas added dropwise
  2. filtrationThe reaction mixture was filtered through Celite, and 6M hydrochloric acid
  3. additionwas added to the filtrate
  4. additionfollowed by addition of ethyl acetate
  5. customthe organic phase was separated
  6. washAfter the resultant organic phase was washed with a saturated sodium chloride solution
  7. dry with materialthe washed phase was dried over anhydrous magnesium sulfate
  8. distillationthe solvent was distilled out under reduced pressure
  9. dissolutionThe resultant residue was dissolved in 30 mL of methylene chloride, to which 20 μL of N,N-dimethylformamide and 1.5 mL of oxalyl chloride
  10. additionwere added successively
  11. stirringthis solution was stirred for 30 minutes at room temperature
  12. additionThe reaction mixture, to which 20 mL of methanol was added dropwise
  13. stirringwas stirred for 30 minutes at room temperature
  14. additionafter water was added
  15. customthe organic phase was separated
  16. washAfter the resultant organic phase was washed with a saturated sodium chloride solution
  17. dry with materialthe washed phase was dried over anhydrous magnesium sulfate
  18. distillationthe solvent was distilled out under reduced pressure

Sources & evidence

ORD record
ord-bba1e34fff054b7199caaa4f89d0879e
Source dataset
uspto-grants-2010_08
Patent number
US07772285B2

Reaction notes

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