Hydrochloric Acid → 5-Bromo-3-(dichloromethyl)-2-nitrothiophene

Temperatur

-78 °C

A solution of 2-bromo-5-nitrothiophene (29 g, 139 mmol) and chloroform (12.37 mL, 153 mmol) in DMF (110 mL) was added dropwise to a solution of potassium tert-butoxide (62.6 g, 558 mmol) in THF (225 mL)/DMF (180 mL). The internal temperature was monitored and maintained at <−60° C. during the addition. Upon complete addition, the reaction was stirred at −78° C. for 30 minutes. 2 N HCl was added and the products were extracted into EtOAc (3×). The combined organic extracts were washed with brine, dried over MgSO4, filtered, and concentrated in vacuo. Purification of the residue by flash silica gel column chromatography (0-10% EtOAc-hexanes) gave the title compound as a brown oil.

1. temperaturemaintained at <−60° C. during the addition
2. additionUpon complete addition
3. extractionthe products were extracted into EtOAc (3×)
4. washThe combined organic extracts were washed with brine
5. dry with materialdried over MgSO4
6. filtrationfiltered
7. concentrationconcentrated in vacuo
8. customPurification of the residue by flash silica gel column chromatography (0-10% EtOAc-hexanes)

ORD-Eintrag

ord-7fca4b71b7804915bee72842cc7079ce

Quelldatensatz

uspto-grants-2013_02

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08367706B2