N,N,N',N'-Tetramethylethylenediamine → 2-methyl-8H-indeno[2,1-b]thiophen-8-one

Participants

Reaction Conditions

Reaction Steps

A solution of 12.88 g (0.074 mol) of 2-methyl-4-phenylthiophene, 23.4 mL (0.16 mol) of TMEDA in 200 mL of diethyl ether (ether) was treated with 100 mL (0.16 mol) of 1.6M BuLi in hexane under stirring at −40° C. Then the reaction mixture was allowed to warm up to room temperature (r.t.) and was stirred for 3 h (white precipitate forms). The reaction mixture was cooled to −40° C. and treated with 8.76 g (0.075 mol) of ethyl N,N-dimethylcarbamate in 25 mL of ether. Then the reaction mixture was allowed to warm up to r.t. and was stirred overnight. Resulting mixture was treated with 10% aqueous NH4Cl, the organic layer was separated and the organic phase was washed with 10% aqueous solution of NH4Cl and then dried by anhydrous Na2SO4. Solvent was evaporated and the residue was washed with methanol. Yield 6.8 g (46%) of red crystals.

Provenance & Evidence