p-Toluenesulfonic acid → 8-t-Butyl-2-(4,6-dimethylpyrimid-2-ylaminomethyl)-1,4-dioxaspiro(4,5)decane

Beteiligte Stoffe

Reaktionsschritte

3-(4,6-dimethylpyrimid-2-ylamino)-propane-1,2-diol (4.0 g, 20 mmol), 4-t-butyl cyclohexanone (3.08 g, 20 mmol) and p-toluenesulfonic acid (4.3 g, 22 mmol) in 50 ml benzene were refluxed on a water trap for 1 hour. The reaction mixture was washed twice with saturated aqueous sodium carbonate (50 ml), dried with magnesium sulphate and evaporated in vacuum. Kugelrohr- distillation of the resulting oil yielded 6.0 g of a colourless oil (b.p. 200° C./0.2 mbar) which was recrystallised from light petroleum to yield 5.0 g of colourless crystals (m.p. 121°-124° C.). GLG-MS analysis indicates an approximately 1:1 mixture of diastereoisomers (cis/trans).

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