Dimethylformamide → 3,4-Dicyanothiophene

Temperature

180 °C

3,4-Dibromothiophene (12.5 ml, 113 mmol) is combined with CuCN (30.4 g, 339 mmol) in DMF (40 ml) in a dry flask under nitrogen utilizing an over-head stirrer. The reaction is allowed to reflux at 180° C. for 5 h. The dark mixture is then poured into a solution of FeCl3 (113.6 g, 700 mmol) in 1.7M HCl (200 ml) and heated at 65° C. for 0.5 h, again using the over-head stirrer. The reaction is cooled to rt and extracted with CH2Cl2 (7×300 ml). Each extract is washed individually with 200 ml each 6M HCl (2×), water, saturated NaHCO3, and water. The organics are then combined, dried over MgSO4, filtered, and concentrated, affording 10.49 g (69%) of 3,4-dicyanothiophene as a fluffy tan solid. HRMS (EI) calcd for C6H2N2S: 133.9939, found 133.9929 (M+).

1. temperatureheated at 65° C. for 0.5 h
2. temperatureThe reaction is cooled to rt
3. extractionextracted with CH2Cl2 (7×300 ml)
4. washEach extract is washed individually with 200 ml each 6M HCl (2×), water, saturated NaHCO3, and water
5. dry with materialdried over MgSO4
6. filtrationfiltered
7. concentrationconcentrated

ORD record

ord-8eea9e5970f347d18378c4f96de7dc67

Source dataset

uspto-grants-2005_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06911543B2