2-(Tri-n-butylstannyl)thiophene → 2-(4-Isopropoxyphenoxy)-5-thien-2-yl-1,3,4-thiadiazole

HRID 404889Notes

Reaction equation

Br[C:2]1[S:3][C:4]([O:7][C:8]2[CH:13]=[CH:12][C:11]([O:14][CH:15]([CH3:17])[CH3:16])=[CH:10][CH:9]=2)=[N:5][N:6]=1.C([Sn](CCCC)(CCCC)[C:23]1[S:24][CH:25]=[CH:26][CH:27]=1)CCC>COCCOC>[CH:15]([O:14][C:11]1[CH:12]=[CH:13][C:8]([O:7][C:4]2[S:3][C:2]([C:23]3[S:24][CH:25]=[CH:26][CH:27]=3)=[N:6][N:5]=2)=[CH:9][CH:10]=1)([CH3:17])[CH3:16]

Participants

Conditions

Temperature: 25 °C

Procedure

A solution of Example 24C (0.58 g, 1835 mmol) and 2-tributylstannylthiophene (0.816 ml, 2.57 mmol) in DME (15 mL) was degassed by bubbling nitrogen into the reaction mixture via a 20-gauge needle for 10 minutes. PdCl2(PPh3)2 was added and the reaction was heated at reflux under a nitrogen atmosphere for 20 hours. The reaction was cooled to 25° C. and concentrated under reduced pressure on a rotary evaporator to provide 1.6 g of a golden oil. The concentrate was purified by flash chromatography on silica gel eluting with a solvent gradient from 1% to 15% ethyl acetate in hexanes to provide 0.51 g (88%) of the title compound as a pale purple oil which crystallized on standing, 1H NMR (300 MHz, DMSO-d6) δ ppm 7.79 (d, J=5.15 Hz, 1H) 7.66 (d, J=3.68 Hz, 1H) 7.40 (d, J=9.19 Hz, 2H) 7.18 (dd, J=5.15, 3.68 Hz, 1H) 7.03 (d, J=9.19 Hz, 2H) 4.64 (heptet, J=5.88 Hz, 1H) 1.28 (d, J=5.88 Hz, 6H); MS (DCI) m/z 319 (M+H)+.

Workup

customby bubbling nitrogen into the reaction mixture via a 20-gauge needle for 10 minutes
additionPdCl2(PPh3)2 was added
temperaturethe reaction was heated
temperatureat reflux under a nitrogen atmosphere for 20 hours
concentrationconcentrated under reduced pressure on a rotary evaporator

Sources & evidence

ORD record: ord-3aa0516f475b423facc11f832608f48d
Source dataset: uspto-grants-2014_06
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08748627B2

Reaction notes

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