HCID 59006697, compound → Benzene, 2-ethynyl-1,4-difluoro-

Temperature

-55 °C

The title compound of Example 37.1 (10.2 g, 48.7 mmol) was dissolved in dry THF (63 mL), cooled on a dry ice/isopropanol bath to −55° C. and butyl lithium (2.5 M, 42 mL, 105 mmol) was added within 30 min at a rate that kept the temperature below −40° C. LC/MS showed good conversion 20 min after the addition of BuLi and stirring. The mixture was warmed up to 0° C. with the aid of a water bath. At 0° C. the mixture was quenched with potassium hydrogen sulfate (2 M solution) until a neutral aqueous phase was achieved. Diethyl ether was added and the water phase was extracted twice with a small amount of diethyl ether. The organic phases were combined and dried (MgSO4), filtered and carefully evaporated using only heat. The solvent was removed by distillation under normal air pressure with the oil bath temperature at 80° C. The remaining residue was distilled in vacuo, and the fraction at 30° C./0 mmHg was collected. Yield 51%, 3.8 g.

1. customthe temperature below −40° C
2. customconversion 20 min
3. temperatureThe mixture was warmed up to 0° C. with the aid of a water bath
4. customAt 0° C. the mixture was quenched with potassium hydrogen sulfate (2 M solution) until a neutral aqueous phase
5. additionDiethyl ether was added
6. extractionthe water phase was extracted twice with a small amount of diethyl ether
7. dry with materialdried (MgSO4)
8. filtrationfiltered
9. customcarefully evaporated
10. temperatureusing only heat
11. customThe solvent was removed by distillation under normal air pressure with the oil bath temperature at 80° C
12. distillationThe remaining residue was distilled in vacuo
13. customthe fraction at 30° C./0 mmHg was collected

ORD record

ord-d2433277529146578a3be4a2ad1202c3

Source dataset

uspto-grants-2010_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07678796B2