2-Thiophenecarboxaldehyde → Di(3-thienyl)methanol

Temperature

-78 °C

The solution containing 1.87 mL (20 mmol) of 3-bromothiophene, 3 mL of tetrahydrofuran, and 10 mL of ether was cooled to −78° C. under N2. To the cooled solution was then added 8 mL of n-BuLi ([2.5] M in hexane) drop wise, while maintaining the reaction temperature below −70° C. The reaction solution turned to white cloudy. The suspension was allowed to stir 15 min at <−70° C. After 15 min, a solution containing 1.75 mL (20 mmol) of 2-thiophenecarboxaldehyde and 3 mL of tetrahydrofuran was added drop wise while maintaining the reaction temperature below −70° C. After the addition, the reaction suspension was allowed to stir 1 hr at −78° C. and slowly warmed to −10° C. over 2 hr. After 2 hr, the reaction was stopped by adding 50 mL of a saturated solution of NH4Cl and 100 mL of dichloromethane. The aqueous solution was separated from the organic phase. After removing the aqueous layer, the organic layer was washed with brine, dried over MgSO4, and concentrated under reduced pressure. The concentrated sample was purified by flashy chromatography (hexane:ethyl acetate, from 10 to 15% ethyl acetate over 16 column volume) to obtain 2.12 gm (53.9%) of yellow solids; 1H NMR 500 MHz (CDCl3) δ 7.29 (d, 1H), 7.29 (d, 1H), 7.22 (t, 1H), 7.21 (t, 1H), 7.05 (d, 1H), 7.04 (d, 1H), 5.97 (d, 1H), 2.22 (d, 1 H).

1. temperaturewhile maintaining the reaction temperature below −70° C
2. waitAfter 15 min
3. additionwas added drop wise
4. temperaturewhile maintaining the reaction temperature below −70° C
5. additionAfter the addition
6. stirringto stir 1 hr at −78° C.
7. temperatureslowly warmed to −10° C. over 2 hr
8. waitAfter 2 hr
9. customThe aqueous solution was separated from the organic phase
10. customAfter removing the aqueous layer
11. washthe organic layer was washed with brine
12. dry with materialdried over MgSO4
13. concentrationconcentrated under reduced pressure
14. customThe concentrated sample was purified by flashy chromatography (hexane:ethyl acetate, from 10 to 15% ethyl acetate over 16 column volume)

ORD record

ord-ab0e1b55aea748229b0ff5b4265f22bc

Source dataset

uspto-grants-2008_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07435822B2