Sulfur Dioxide → 5-Methyl-thiophene-3-sulfonic acid lithium salt

Participants

Reaction Steps

To a solution of 4-bromo-2-methyl-thiophene (1.594 g, 9.00 mmol) in 5.0 mL of diethyl ether was added dropwise 2.1 mL of tert-butyllithium in pentane (1.7 M, 09 eq.). After stirring for 20 Min. at −78° C., sulfur dioxide (condensed, ca. 4 mL) was added dropwise and the reaction mixture kept for another 30 min at this temperature. The dry ice cooling bath was removed and the reaction mixture diluted with heptane; the precipitated solid was collected, washed with some heptane and dried at high vacuum to yield 1.100 g of the title compound as white solid.

Provenance & Evidence