In scheme 14476001a hexadecanol is reacted with phosphoroxy chloride in the presence of triethylamine in tetrahydrofuran with subsequent condensation with ethanolamine in dioxane/triethylamine. Hydrolysis with aqueous hydrochloric acid and methylation with dimethyl sulfate in the presence of potassium carbonate yields hexadecyl phosphocholine.
The synthesis of [14C]-labeled hexadecylphosphocholine has been described: By condensation of [14C]-labeled phosphocholine (I) with hexadecyl bromide (II) by means of tetrabutylammonium hydroxide in acetonitrile. The same method is used to obtain unlabeled hexadecylphosphocholine.
An improved synthesis of ilmofosine has been reported: The reaction of 2-(hydroxymethyl)-2-propenoic acid ethyl ester (I) with PBr3 in ethyl ether gives the corresponding 2-bromomethyl derivative (II), which is condensed with hexadecylthiol (III) by means of triethylamine to afford 2-(hexadecylsulfanyl)-2-propenoic acid ethyl ester (IV). The reduction of (IV) with diisobutylaluminum hydride (DIBAL) yields 3-(hexadecylsulfanyl)-2-methylene-1-propanol (V), which is methylated with NaH and MeI to the methyl ether (VI). The hydroboration of (VI) with BH3.S(CH3)2 followed by oxidation with NaBO3 gives 3-(hexadecylsulfanyl)-2-(methoxymethyl)-1-propanol (VII), which is finally phosphorylated with PCl3 and condensed with choline p-toluenesulfonate (VIII).
The reaction of 2-(hydroxymethyl)propenoic acid ethyl ester (I) with PBr3 and then with hexadecyl mercaptane (II) and TEA gives 2-(hexadecylsulfanylmethyl)propenoic acid methyl ester (III), which is reduced with DIBAL in THF to the corresponding carbinol (IV). The methylation of (IV) with methyl iodide and NaH in THF affords the methyl ether (V), which is hydroxylated at the double bond with BH3/Me2S and NaBO3 providing 3-(hexadecylsulfanyl)-2-(methoxymethyl)-1-propanol (VI). Finally this compound is treated with POCl3 and TEA in chloroform and condensed with choline tosylate (VII) to furnish the target phosphorylcholine derivative.
The reaction of hexadecanol (I) with the cyclic chlorophosphate ester (II) and DIEA in dichloromethane gives the cyclic hexadecyl phosphate (III), which is brominated with Br2 in the same solvent to yield the mixed 2-bromoethyl hexadecyl bromophosphate ester (IV). Finally this compound is condensed with trimethylamine in acetonitrile/isopropanol/chloroform to furnish the target phosphorylcholine ester.
The reaction of hexadecanol (I) with the cyclic chlorophosphate ester (II) and TEA in tert-butyl methyl ether gives the cyclic hexadecyl phosphate (III), which is condensed with TEA in hot acetonitrile to afford the target phosphorylcholine ester.
The reaction of (R)-O-benzylglycidol (I) with octadecanol (II) by means of NaH in hot DMF gives (R)-1-(benzyloxy)-3-(octadecyloxy)-2-propanol (III), which is methylated with methyl iodide and NaH in DMF yielding the corresponding methyl ether (IV). The debenzylation of (IV) with H2 over Pd/C in THF affords the primary alcohol (V), which is finally treated with POCl3/pyridine in CHCl3 and condensed with choline tosylate (VI) to furnish the target phosphorylcholine derivative.