3,4-Dichloro-1,2,5-thiadiazole → 1,2,5-Thiadiazole, 3-chloro-4-(2-thienyl)-

HRID 1167986Notes

Reaction equation

HRID 1167986 reaction equation
C([Sn](CCCC)(CCCC)[C:6]1[S:7][CH:8]=[CH:9][CH:10]=1)CCC.[Cl:19][C:20]1[C:24](Cl)=[N:23][S:22][N:21]=1>C1(C)C=CC=CC=1.C1C=CC([P]([Pd]([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)([P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)[P](C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)(C2C=CC=CC=2)C2C=CC=CC=2)=CC=1>[Cl:19][C:20]1[C:24]([C:6]2[S:7][CH:8]=[CH:9][CH:10]=2)=[N:23][S:22][N:21]=1

Participants

5

Reactant 2

HCID 798043,4-Dichloro-1,2,5-thiadiazoleHCID 27793732-(Tri-n-butylstannyl)thiophene

Product 1

HCID 120252621,2,5-Thiadiazole, 3-chloro-4-(2-thienyl)-Yield 54%

Reagents, catalysts & solvents 2

HCID 178418397HCID 178418397, compoundCatalystHCID 1140TolueneSolvent

Procedure

0.92 g (0.00246 mol) of 2-(tributylstannyl)thiophene and 0.12 g (0.0001 mol) of tetrakis(triphenylphosphine)palladium(0) were added to a solution of 0.33 g (0.00213 mol) of 3,4-dichloro-1,2,5-thiadiazole in 4 mL of toluene under nitrogen and heated at reflux. After 3 and 6 h respectively, 0.04 g (2 times 2.5×10−5 mol) of tetrakis (triphenylphosphine)palladium(0) were added. After 24 h of reflux (quantitative HPLC: 54% of product formed, all the stannane was consumed), the reaction medium was diluted with 5 mL of ethyl acetate and vigorously stirred with 10 mL of a 1M aqueous solution of KF for 2 h. After filtration through celite, the aqueous phase was re-extracted with ethyl acetate, the combined organic phases were dried over magnesium sulfate and concentrated.

Workup

  1. temperatureheated
  2. temperatureat reflux
  3. temperatureAfter 24 h of reflux (quantitative HPLC

Sources & evidence

ORD record
ord-1dee37e1ce724a039212b22216fc9746
Source dataset
uspto-grants-2003_09
Patent number
US06620940B1

Reaction notes

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