N,N,N',N'-Tetramethylethylenediamine → HCID 13822798, compound

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Reaction Conditions

Reaction Steps

At 0° C., a solution of lithium bis(trimethylsilyl)amide is prepared from 4 ml of anhydrous toluene, 0.32 ml of anhydrous, freshly distilled hexamethyldisilazane (1.5 mmol) and 0.85 ml of n-butyllithium in hexane (1.4 mmol). A solution of 533 mg of 3-[2-bromo-1-(tert-butyldimethylsilyl)-6-methyl-8α-ergolinyl]-1,1-diethylurea (1 mmol) in 50 ml of anhydrous, freshly distilled toluene is added to this solution, and the mixture is stirred for another 15 minutes. After adding 0.8 ml of distilled tetramethylethylenediamine, the mixture is cooled to -90° C., combined with 4.5 ml of tert-butyllithium (6.3 mmol), further stirred for two minutes, and the thus-formed 2-lithium compound is made to react with 2.2 g of diphenyldisulfide (10 mmol), dissolved in 10 ml of anhydrous, freshly distilled toluene, at -70° C. After 30 minutes of agitation at -70° C., water is added, the toluene phase is separated, and the aqueous phase is extracted by shaking with methylene chloride. The organic phases are dried with sodium sulfate and evaporated, the residue is chromatographed on silica gel. The yield is 523 mg of 3-[1-(tertbutyldimethylsilyl)-6-methyl-2-phenylthio-8α-ergolinyl]-1,1-diethylurea (70% of theory). This compound is dissolved in 10 ml of methanol and stirred with 1 ml of 14N potassium hydroxide solution at room temperature for 20 hours. Water is added to this mixture, the latter is stirred in an ice bath for 30 minutes, and the precipitate is suctioned off, yielding 344 mg (82% of theory). Recrystallization from methanol yields 229 mg of the final product (total yield 51%),

Provenance & Evidence