Bromine → 5,7-Difluorobenzo[d]thiazol-2-amine

HRID 9570

Reaction equation

HRID 9570 reaction equation
[F:1][C:2]1[CH:3]=[C:4]([NH:9][C:10]([NH2:12])=[S:11])[CH:5]=[C:6]([F:8])[CH:7]=1.BrBr>ClCCCl>[F:1][C:2]1[CH:7]=[C:6]([F:8])[C:5]2[S:11][C:10]([NH2:12])=[N:9][C:4]=2[CH:3]=1

Participants

4

Reactant 2

HCID 24408BromineHCID 2783293(3,5-Difluorophenyl)thiourea

Product 1

HCID 150505645,7-Difluorobenzo[d]thiazol-2-amineYield 90.7%

Reagents, catalysts & solvents 1

HCID 111,2-DichloroethaneSolvent2×

Conditions

Temperature
10 °C

Procedure

To a suspension of N-(3,5-difluorophenyl) thiourea (3.40 g, 18.07 mmol) in DCE (95 mL) was added a solution of bromine in DCE (5 mL) below 30° C. The mixture was heated at reflux for 2.5 h, then cooled to 10° C., and the precipitate formed was collected by filtration and washed with DCE. The solid was stirred with water (200 mL), basified by treatment with conc. ammonium hydroxide, filtered, and dried in a vacuum oven to afford 5,7-difluoro-1,3-benzothiazol-2-amine (3.05 g, 90%). ret. time 2.18; m/z 187.1 (NH+); 1H NMR (400 MHz, DMSO-d6) δ 6.92 (m, 1H), 7.00 (m, 2H), 7.92 (s, 2H).

Workup

  1. temperatureThe mixture was heated
  2. temperatureat reflux for 2.5 h
  3. customthe precipitate formed
  4. filtrationwas collected by filtration
  5. washwashed with DCE
  6. filtrationfiltered
  7. customdried in a vacuum oven

Sources & evidence

ORD record
ord-4f7aa1f4483046469aab193d0211f406
Source dataset
uspto-grants-2006_08
Patent number
US07091228B2

Linked notes

Loading…