2-(Tri-n-butylstannyl)thiophene → 5,6-Difluoro-4,7-di(thiophen-2-yl)benzo[c][1,2,5]thiadiazole

HRID 1024821Notes

Reaction equation

Br[C:2]1[C:7]2=[N:8][S:9][N:10]=[C:6]2[C:5](Br)=[C:4]([F:12])[C:3]=1[F:13].C([Sn](CCCC)(CCCC)[C:19]1[S:20][CH:21]=[CH:22][CH:23]=1)CCC>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.C1(C)C=CC=CC=1>[F:13][C:3]1[C:4]([F:12])=[C:5]([C:21]2[S:20][CH:19]=[CH:23][CH:22]=2)[C:6]2[C:7]([C:2]=1[C:19]1[S:20][CH:21]=[CH:22][CH:23]=1)=[N:8][S:9][N:10]=2

Participants

Conditions

Temperature: 105 °C

Procedure

4,7-Dibromo-5,6-difluoro-benzo[1,2,5]thiadiazole (0.29 g, 1 mmol), tributyl-thiophen-2-yl-stannane (0.86 g, 2.3 mmol), and Pd(PPh3)4 (20 mg) were combined into a 50-mL Schlenk flask. The system was vacuumed and backfilled with argon for three cycles before 20 mL anhydrous toluene was added. The mixture was heated at 105° C. for 4 days. After the reaction was cooled down, the solvent was removed by rotary evaporation. The product was further purified by silica gel column with toluene/hexane (v/v, 1/2) as the eluent and recrystallization from a hexane/iso-propoanol mixture. The final product (0.276 g, 93.0% yield) was obtained as red needle crystals after being dried in vacuo. 1H NMR (CDCl3, 500 MHz): δ 8.33 (d×d, 2H, J=4.0 Hz×1.0 Hz), δ 7.66 (d×d, 2H, J=5.5 Hz×1.0 Hz), δ 7.30 (d×d, 2H, J=5.5 Hz×4.0 Hz)

Workup

additionwas added
temperatureAfter the reaction was cooled down
customthe solvent was removed by rotary evaporation
customThe product was further purified by silica gel column with toluene/hexane (v/v, 1/2) as the eluent and recrystallization from a hexane/iso-propoanol mixture

Sources & evidence

ORD record: ord-098fae2534014c3fa5ead403e3c3f7cb
Source dataset: uspto-grants-2014_05
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08723028B2

Reaction notes

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