4,7-Dibromo-2,1,3-benzothiadiazole → 4,7-Di(thiophen-2-yl)benzo(c)(1,2,5)thiadiazole

HRID 531172

Reaction equation

HRID 531172 reaction equation
Br[C:2]1[C:10]2[C:6](=[N:7][S:8][N:9]=2)[C:5](Br)=[CH:4][CH:3]=1.C([Sn](CCCC)(CCCC)[C:17]1[S:18][CH:19]=[CH:20][CH:21]=1)CCC>O1CCCC1>[S:18]1[CH:19]=[CH:20][CH:21]=[C:17]1[C:2]1[C:10]2[C:6](=[N:7][S:8][N:9]=2)[C:5]([C:19]2[S:18][CH:17]=[CH:21][CH:20]=2)=[CH:4][CH:3]=1

Participants

4

Reactant 2

HCID 6263614,7-Dibromo-2,1,3-benzothiadiazole2×HCID 27793732-(Tri-n-butylstannyl)thiophene

Product 1

HCID 3962944,7-Di(thiophen-2-yl)benzo(c)(1,2,5)thiadiazole

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

According to what is described by Kitamura et al. in “Chemistry of Material” (1996), Vol. 8, pages 570-578, for example, 4,7-di-2-thienyl-2,1,3-benzothia-diazole (DTB) can be prepared by reacting 4,7-dibromo-2,1,3-benzothiadiazole and tri-n-butyl(thien-2-yl)stannane, in the presence of tetrahydrofuran, at 66° C., for 3 hours. Bis(triphenylphosphine)palladium-(II)chloride [PdCl2(PPh3)2] is used as catalyst, in a quantity equal to 2 moles per 100 moles of 4,7-dibromo-2,1,3-benzothiadiazole. At the end of the reaction, the solvent is removed by evaporation at reduced pressure and the residue obtained is purified by elution on a silica gel chromatographic column using a mixture of methylene chloride/hexane (1/1 vol/vol) as eluent, obtaining 4,7-di-2-thienyl-2,1,3-benzothiadiazole (DTB) with a yield equal to 82%.

Workup

  1. customcan be prepared
  2. customAt the end of the reaction
  3. customthe solvent is removed by evaporation at reduced pressure
  4. customthe residue obtained
  5. customis purified by elution on a silica gel chromatographic column
  6. additiona mixture of methylene chloride/hexane (1/1 vol/vol) as eluent

Sources & evidence

ORD record
ord-6e424d0149d0477ca912322c0c27592f
Source dataset
uspto-grants-2016_05
Patent number
US09353125B2

Linked notes

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