Sulfuric Acid → HCID 66686367, compound

HRID 1778391Notes

Reaction equation

HRID 1778391 reaction equation
C(C([NH:7][C:8]1[C:13]([C:14]([O:16][CH3:17])=[O:15])=[C:12]2[O:18][CH2:19][C:20]3[CH:21]=[N:22][S:23][C:24]=3[C:11]2=[CH:10][CH:9]=1)=O)(C)(C)C.S(=O)(=O)(O)O>CO.C(OCC)(=O)C>[NH2:7][C:8]1[C:13]([C:14]([O:16][CH3:17])=[O:15])=[C:12]2[O:18][CH2:19][C:20]3[CH:21]=[N:22][S:23][C:24]=3[C:11]2=[CH:10][CH:9]=1

Participants

5

Reactant 2

HCID 1118Sulfuric AcidHCID 666935204H-[1]Benzopyrano[3,4-d]isothiazole-6-carboxylic acid, 7-[(2,2-dimethyl-1-oxopropyl)amino]-, methyl ester2×

Product 1

HCID 66686367HCID 66686367, compoundYield 66%

Reagents, catalysts & solvents 2

HCID 887MethanolSolventHCID 8857Ethyl AcetateSolvent

Procedure

A suspension of methyl 7-tert-butylcarbonylamino-4H-chromeno[3,4-d]isothiazole-6-carboxylate (Intermediate 75, 0.690 g) in methanol (30 mL) was treated with concentrated sulfuric acid (1.2 mL) and the resultant mixture was heated at 75° C. in a sealed vessel overnight. The mixture was cooled, diluted with ethyl acetate and washed with saturated aqueous sodium bicarbonate solution. The aqueous phase was saturated with sodium chloride then extracted with ethyl acetate again. The combined organic layers were dried (Na2SO4), filtered and the filtrate was concentrated in vacuo. The residue was purified by chromatography on silica, eluting with a mixture of ethyl acetate and cyclohexane, with a gradient of 15-45% to give methyl 7-amino-4H-chromeno[3,4-d]isothiazole-6-carboxylate (0.345 g) as a yellow solid.

Workup

  1. temperatureThe mixture was cooled
  2. washwashed with saturated aqueous sodium bicarbonate solution
  3. extractionthen extracted with ethyl acetate again
  4. dry with materialThe combined organic layers were dried (Na2SO4)
  5. filtrationfiltered
  6. concentrationthe filtrate was concentrated in vacuo
  7. customThe residue was purified by chromatography on silica
  8. washeluting with a mixture of ethyl acetate and cyclohexane, with a gradient of 15-45%

Sources & evidence

ORD record
ord-bdfde3b917a94109813d5129010aa28d
Source dataset
uspto-grants-2016_02
Patent number
US09266896B2

Reaction notes

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