Diethyl Ether → HCID 86737909, compound

Participants

Reaction Steps

Methyl pyrrole-3-carboxylate (1 g., 8 mmoles) was dissolved in 10 ml. of methylene chloride and stirred under nitrogen. A solution of ethylsulfenyl chloride in carbon tetrachloride as prepared above (estimated 10 mmoles) was added, followed by stannic chloride (2.3 ml., 20 mmoles). The reaction mixture was stirred at room temperature for 2 hours. A precipitate formed. A mixture of ice and water (approximately 10 ml.) and ethyl acetate (20 ml.) was added to the reaction mixture, which was then added to 100 ml. of ether. The organic phase was washed twice with 50 ml. of water, once with 50 ml. of 1 N sodium hydroxide, twice more with 25 ml. portions of water and finally concentrated to an oil (1 g.). The reaction was repeated on 5.5 times this scale. In this case, the supernatant was decanted from the precipitate which had formed by the end of the reaction period. Water (100 ml.) and ether (approximately 300 ml.) was added to the supernatant. The organic phase was washed with water and concentrated to an oil (1.3 g.). The precipitate was dissolved in 150 ml. of ethyl acetate and 100 ml. of water. The ethyl acetate layer was washed with 50 ml. of water, filtered and concentrated to dryness (4.8 g.). The three crude products above were combined (approximately 6.5 g.), dissolved in approximately 5 ml. of ethyl acetate and chromatographed on 400 ml. of silica gel, eluted with ethyl acetate-1/hexane-6/5% acetic acid. The purification was monitored by thin layer chromatography (silica gel with the same eluant). Middle cuts containing clean product (Rf 0.4) were concentrated to dryness and triturated with hexane to yield slightly gummy crystals (1.15 g.). Recrystallization of 444 mg. of crude from ether/hexane gave purified methyl 5-ethylthiopyrrole-3-carboxylate (140 mg., m.p. 67°-70° C.). Additional crude product (approximately 300 mg.) was recovered by evaporation of the recrystallization mother liquor.

Provenance & Evidence