Process for the preparation of dispiro 1,2,4-trioxolane antimalarials (OZ277)
This invention relates to an improved process for the preparation of a compound of Formula (I), salts of the free base cis-adamantane-2-spiro-3′-8′-[[[(2′-amino-2′-methyl propyl)amino]carbonyl]methyl]-1′,2′,4′-trioxaspiro[4.5]decane wherein X can be an anion.
1. A process for the preparation of a compound of Formula I, salt of the free base cis-adamantane-2-spiro-3′-8′-[[[(2′-amino-2′-methyl propyl)amino]carbonyl]methyl]-1′,2′,4′-trioxaspiro [4.5] decane
wherein X is an anion selected from acetate, adipate, alginate, citrate, aspartate, benzoate, benzene sulfonate, bisulfate, butyrate, camphorate, camphor sulfonate, digluconate, glycerophosphate, glycolate, malonate, hemisulfate, heptanoate, hexanoate, fumarate, hydrochloride, hydrobromide, hydroiodide, isethionate, lactate, maleate, methane sulfonate, nicotinate, 2-naphthalene sulfonate, oxalate, palmitoate, pectinate, persulfate, 3-phenylpropionate, picrate, pivalate, propionate, succinate, tartrate, thiocyanate, phosphate, glutamate, bicarbonate, p-toluene sulfonate or undecanoate, the process comprising,
a) reacting a compound of Formula II (wherein R is alkyl) with a compound of Formula III (wherein R is alkyl)
to give a compound of Formula IV;
b) hydrolyzing the compound of Formula IV to give a compound of Formula V;
c) reacting the compound of Formula V with an activating agent that forms a mixed anhydride with the compound of Formula V and 1,2-diamino-2-methyl propane to give a compound of Formula VI; and
d) reacting the compound of Formula VI with an acid of Formula HX (wherein X is the same as defined earlier) to give a compound of Formula I.
2. The process according to claim 1 , wherein the activating agent is selected from methyl chloroformate, ethyl chloroformate, propyl chloroformate, n-butyl chloroformate, isobutyl chloroformate and pivaloyl chloride.
3. The process according to claim 1 , wherein the reaction of a compound of Formula II with a compound of Formula III to give a compound of Formula IV is carried out in a hydrocarbon solvent, chlorinated hydrocarbon solvent or mixture(s) thereof.
4. The process according to claim 3 , wherein the hydrocarbon solvent is hexane, cyclohexane or mixture(s) thereof.
5. The process according to claim 3 , wherein the chlorinated hydrocarbon solvent is dichloromethane, dichloroethane or mixture(s) thereof.
6. The process according to claim 1 , wherein the hydrolysis of a compound of Formula IV to give a compound of Formula V is carried out in an alcoholic solvent, water or mixture(s) thereof.
7. The process according to claim 6 , wherein the alcoholic solvent is methanol, ethanol, isopropanol or mixture(s) thereof.
8. The process according to claim 1 , wherein the hydrolysis of a compound of Formula IV to give a compound of Formula V is carried out in the presence of an inorganic base.
9. The process according to claim 8 , wherein the inorganic base is sodium hydroxide, potassium hydroxide or mixture(s) thereof.
10. The process according to claim 1 , wherein the reaction of a compound of Formula V with an activating agent and 1,2-diamino-2-methyl propane to give a compound of Formula VI is carried out in a chlorinated hydrocarbon solvent, polar aprotic solvent or mixture(s) thereof.
11. The process according to claim 10 , wherein the chlorinated hydrocarbon solvent is dichloromethane, dichloroethane or mixture(s) thereof.
12. The process according to claim 10 , wherein the polar aprotic solvent is dimethylformamide, dimethylsulfoxide or mixture(s) thereof.
13. The process according to claim 10 , wherein the reaction of a compound of Formula V with an activating agent and 1,2-diamino-2-methyl propane to give a compound of Formula VI is carried out in the presence of an organic base.
14. The process according to claim 13 , wherein the organic base is trimethylamine, triethylamine, isopropylamine or mixture(s) thereof.
15. The process according to claim 1 , wherein the reaction of a compound of Formula VI with an acid of Formula HX to give a compound of Formula I is carried out in an alcoholic solvent, hydrocarbon solvent or mixture(s) thereof.
16. The process according to claim 15 , wherein the alcoholic solvent is methanol, ethanol, isopropanol or mixture(s) thereof.
17. The process according to claim 15 , wherein the hydrocarbon solvent is hexane, heptane or mixture(s) thereof.