3,6-Dichloropyridazine → 3-Chloro-6-(thiophen-2-yl)pyridazine

HRID 2223001Notes

Reaction equation

C([Sn]([C:14]1[S:15][CH:16]=[CH:17][CH:18]=1)(CCCC)CCCC)CCC.[Cl:19][C:20]1[N:21]=[N:22][C:23](Cl)=[CH:24][CH:25]=1>CN(C=O)C.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>[S:15]1[CH:16]=[CH:17][CH:18]=[C:14]1[C:23]1[N:22]=[N:21][C:20]([Cl:19])=[CH:25][CH:24]=1

Participants

Conditions

Temperature: 80 °C

Procedure

A mixture of tri-n-butylstannylthiophene (6.26 g, 16.78 mmol), 3,6-dichloropyridazine (5.00 g, 33.56 mmol), tetrakis(triphenylphosphine)palladium(0) (0.20 g, 0.17 mmol) and few crystals of 1,2-ditert-butyl of 2,6-di-tert-butyl-4-methylphenolo in dry DMF (50 mL) was deareated twice with nitrogen. The reaction mixture was heated at 80° C. for 6 hours and, after cooling, poured onto water (100 mL). A white precipitate was collected, washed several times with water and dried under vacuum. This solid was taken up with ether (25 mL) and filtered to afford 3.01 g of almost pure product. Finally, this solid was crystallized from MeOH—H2O to give the pure target compound as white crystals (1.56 g, 7.90 mmol, 47.3% yield). Mp 155° C.; 1H NMR (CDCl3) δ 7.75 (1H, d, 2J=11.0), 7.68 (1H, d, 2J=3.6), 7.54 (1H, d, 2J=5.0), 7.51 (1H, d), 7.18 (1H, dd).

Workup

temperatureafter cooling
additionpoured onto water (100 mL)
customA white precipitate was collected
washwashed several times with water
customdried under vacuum
filtrationfiltered
customto afford 3.01 g of almost pure product
customFinally, this solid was crystallized from MeOH—H2O

Sources & evidence

ORD record: ord-788d022602484d1890222766e2d39d7d
Source dataset: uspto-grants-2008_05
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07374702B2

Reaction notes

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