Diethyl Ether → Dicyclohexylamine

Participants

Reaction Steps

1.26 g of (3S)-2-[(2S)-3-benzoylthio-2-methylpropionyl]-1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid dicyclohexylamine salt are suspended in a mixture of 15 ml of 10 % aqueous ammonia and 5 ml of methanol. The mixture is stirred at room temperature for 3.5 hours in nitrogen gas atmosphere. The reaction mixture is condensed to dryness under reduced pressure, and a mixture of ether and n-hexane is added thereto. Crystalline precipitates are collected by filtration, washed with ether and recrystallized from ethanol. 0.85 g of (3S)-2-[(2S)-3-mercapto-2-methylpropionyl]-1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid.dicyclohexylamine salt is thereby obtained as colorless crystals. Yield: 82.7 % M.p. 191°-192° C.(decomp.) (This product begins to gradually decompose at about 172° C.). All the physico-chemical properties of this product are identical with those of the sample obtained in Example 1-(3).

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