Hydrochloric Acid → 6-Chloro[1,3]dioxolo[4,5-f][1,3]benzothiazole

HRID 2399723Notes

Reaction equation

HRID 2399723 reaction equation
N[C:2]1[S:3][C:4]2[CH:10]=[C:9]3[O:11][CH2:12][O:13][C:8]3=[CH:7][C:5]=2[N:6]=1.N(OC(C)(C)C)=O.O.C(OCC)C.[ClH:27]>C(#N)C.[Cu](Cl)Cl>[Cl:27][C:2]1[S:3][C:4]2[CH:10]=[C:9]3[O:11][CH2:12][O:13][C:8]3=[CH:7][C:5]=2[N:6]=1

Participants

7

Reactant 4

HCID 313Hydrochloric AcidHCID 10906Tert-Butyl nitriteHCID 20499002H-[1,3]Dioxolo[4,5-f][1,3]benzothiazol-6-amineHCID 21584184Diethylether water

Product 1

HCID 20498846-Chloro[1,3]dioxolo[4,5-f][1,3]benzothiazole

Reagents, catalysts & solvents 2

HCID 24014Cupric ChlorideCatalystHCID 6342AcetonitrileSolvent2×

Procedure

The product from Step 1 (1.7 g) was partially dissolved in dry acetonitrile (50 cm3) and added in portions to a stirred suspension of copper(II) chloride (1.41 g) and tert-butyl nitrite (1.56 cm3) in dry acetonitrile (15 cm3) at 60° C. The mixture was heated for 1 hr., cooled to ambient temperature, poured into water/diethyl ether and acidified with aqueous 2M hydrochloric acid. The aqueous fraction was separated and extracted with diethylether (3×100 cm3) and the combined organic fractions washed with water (3×50 cm3) and dried (magnesium sulphate). The solution was evaporated under reduced pressure to give a brown solid. The solid was fractionated by absorbing it onto silica and eluting with hexane/ethyl acetate (50:1 by volume) to give the required product as a colourless solid, M+ =213; 1NMR (CDCl3): δ7.36(1H,s): 7.14(1H,s); 6.08(2H,s); mp 131°-2° C.

Workup

  1. temperatureThe mixture was heated for 1 hr
  2. customThe aqueous fraction was separated
  3. extractionextracted with diethylether (3×100 cm3)
  4. washthe combined organic fractions washed with water (3×50 cm3)
  5. dry with materialdried (magnesium sulphate)
  6. customThe solution was evaporated under reduced pressure
  7. customto give a brown solid
  8. customby absorbing it onto silica
  9. washeluting with hexane/ethyl acetate (50:1 by volume)

Sources & evidence

ORD record
ord-e77549971cf3477ebf12f28aee3cd3d7
Source dataset
uspto-grants-1995_09
Patent number
US05451594

Reaction notes

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