| abstract |
NEW MATERIAL:A compound expressed by formula I[R is residue R of amino acid expressed by the formula R.CH(NH 2 )COOH; R, together with formula II, may be form formula III]. n EXAMPLE: Cyclopentane-3-spiro-6-methyl-piperazine-2,5-dione expressed by formula IV. n USE: An immunosuppressive agent. n PREPARATION: Cycloleucine expressed by formula V is made to react with a mixture solution of benzyl alcohol, p-toluenesulfonic acid and toluene while being heated and refluxed and then crystallized in an ether to provide a cycloleucine benzyl ester p-toluenesulfonate expressed by formula VI, which is subsequently subjected to a reaction with an amino acid expressed by formula VII in which the amino group is protected with tert-butyloxycarbonyl group in N-methylmorpholine, etc., to afford a compound expressed by formula VIII. The resultant compound expressed by formula VIII is then dissolved in hydrochloric acid-dioxane and the reaction solution is evaporated to dryness. The obtained solid is subsequently dissolved in a solvent and N-methylmorpholine is then added thereto. The reaction mixture is refluxed while being heated. n COPYRIGHT: (C)1991,JPO&Japio |