Acrolein → 5-(Trifluoromethyl)-3-vinyl-1,3-dihydro-2-benzofuran-1-ol

Temperature

-15 °C

To a solution of N,N,N′-trimethyl-1,2-ethanediamine (4.76 mL, 37.4 mmol) in tetrahydrofuran (150.00 mL) was added a 1.6 M solution of n-butyllithium in hexane (25.7 mL) at −40° C. The colorless solution became light yellow. The cold bath was removed and the reaction stirred for 30 min while warming to −15° C. The reaction was rechilled at −40° C. and 4-trifluoromethylbenzaldehyde (5.00 mL, 37.4 mmol) was added. The reaction was stirred at −50° C. for 35 min before a second addition of a 1.60 M solution of n-butyllithium in hexane was carried out. The reaction was allowed to warm to −25° C. and maintained at −25° C. for 2 h at which time acrolein (2.75 mL, 41.2 mmol) was added. The reaction mixture was stirred overnight and quenched by addition of 30 mL of 6 N HCl aqueous solution. The organic layer was separated and the aqueous phase was extracted with EtOAc twice (2×30 mL). The combined extracts were washed with brine, dried over Na2SO4, evaporated in vacuo and purified by flash chromatography to give the desired product (2.4 g, 28% yield). LC-MS [M+1]=231.2.

1. customThe cold bath was removed
2. customwas rechilled at −40° C.
3. temperatureto warm to −25° C.
4. additionwas added
5. stirringThe reaction mixture was stirred overnight
6. customquenched by addition of 30 mL of 6 N HCl aqueous solution
7. customThe organic layer was separated
8. extractionthe aqueous phase was extracted with EtOAc twice (2×30 mL)
9. washThe combined extracts were washed with brine
10. dry with materialdried over Na2SO4
11. customevaporated in vacuo
12. custompurified by flash chromatography

ORD record

ord-70b5eed64714484092c4c85255da9fa1

Source dataset

uspto-grants-2015_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09067921B2