Ammonia → 6-[(Perfluoroethyl)methoxy]-2-benzothiazolamine

HRID 2254647Notes

Reaction equation

HRID 2254647 reaction equation
[S-:1][C:2]#[N:3].[K+].[F:5][C:6]([F:20])([C:16]([F:19])([F:18])[F:17])[CH2:7][O:8][C:9]1[CH:15]=[CH:14][C:12]([NH2:13])=[CH:11][CH:10]=1.BrBr.N>C(O)(=O)C.O>[F:5][C:6]([F:20])([C:16]([F:17])([F:18])[F:19])[CH2:7][O:8][C:9]1[CH:10]=[CH:11][C:12]2[N:13]=[C:2]([NH2:3])[S:1][C:14]=2[CH:15]=1

Participants

7

Reactant 4

HCID 222AmmoniaHCID 24408BromineHCID 516872Potassium thiocyanateHCID 18539045HCID 18539045, compound

Product 1

HCID 106854606-[(Perfluoroethyl)methoxy]-2-benzothiazolamineYield 38.8%

Reagents, catalysts & solvents 2

HCID 176Acetic AcidSolvent2×HCID 962WaterSolvent

Conditions

Temperature
20 °C

Procedure

Potassium thiocyanate (4.27 g) is added to a solution of 4-(2,2,3,3,3-pentafluoropropoxy)aniline (2.65 g) in acetic acid (25 cc), and the mixture is stirred for 10 minutes at a temperature in the region of 20° C. To the solution thereby obtained, a solution of bromine (0.56 cc) in acetic acid (5 cc) is introduced dropwise in the course of 35 minutes at a temperature of between 22° C. and 35° C., and the mixture is then stirred for 16 hours at a temperature in the region of 20° C. The reaction mixture is poured into a mixture of water and ice (150 cc), alkalinized with 28% strength ammonia solution (35 cc) and extracted 3 times with ethyl acetate (170 cc in total). After settling has taken place, the organic solution is separated and washed with distilled water to pH 8, dried over magnesium sulphate, filtered and evaporated at 50° C. under reduced pressure (20 mm Hg; 2.7 kPa). The product obtained (3.2 g) is purified by chromatography on a column of silica (250 g; particle size: 0.063-0.200 mm) with a mixture of cyclohexane and ethyl acetate (50:50 by volume) as eluant, and recrystallized in toluene (15 cc). 6-(2,2,3,3,3-Pentafluoropropoxy)-2-benzothiazolamine (1.27 g), m.p. 147° C., is obtained.

Workup

  1. customTo the solution thereby obtained
  2. stirringthe mixture is then stirred for 16 hours at a temperature in the region of 20° C
  3. extractionextracted 3 times with ethyl acetate (170 cc in total)
  4. customthe organic solution is separated
  5. washwashed with distilled water to pH 8
  6. dry with materialdried over magnesium sulphate
  7. filtrationfiltered
  8. customevaporated at 50° C. under reduced pressure (20 mm Hg; 2.7 kPa)
  9. customThe product obtained (3.2 g)
  10. customis purified by chromatography on a column of silica (250 g; particle size: 0.063-0.200 mm) with a mixture of cyclohexane and ethyl acetate (50:50 by volume) as eluant
  11. customrecrystallized in toluene (15 cc)

Sources & evidence

ORD record
ord-2c3ec1862bf946ec9014806c52976fb1
Source dataset
uspto-grants-1993_08
Patent number
US05236940

Reaction notes

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