The condensation of N-methyl-N-(1-naphthylmethyl)propargylamine (I) with 1-bromo-2-tert-butylacetylene (II) by means of Cu2Cl2 gives N-methyl-N-(1-naphthylmethyl)-6,6-dimethylhept-2,4-diynylamine (III), which is then reduced selectively with diisobutylaluminurn hydride in toluene.

By reductocondensation of amino (IV) with 6,6-dimethylhept-2-en-4-ynal (VI) by means of NaBH4 in methanol.

The condensation of propenal (VII) with tert-butylacetylene (VIII) by means of butyllithium gives 6,6-dimethylhept-1-en-4-yn-3-ol (IX), which is rearranged with HBr to the allyl isomer 6,6-dimethylhept-2-en-4-yn-1-yl bromide (X). Finally, this compound is condensed with amine (IV) by means of Na2CO3 in DMF.

Addition of formaldehyde to benzothiophene-2-sulfonamide (I), followed by condensation with trimethyl phosphite, furnished the dimethyl (sulfonamidomethyl)phosphonate (II). The phosphonate ester function of (II) was then hydrolyzed by means of bromotrimethylsilane, producing phosphonic acid (III). This was finally coupled to 2-fluoro-4-nitrophenol (IV) using trichloroacetonitrile in hot pyridine to afford the title mono-phosphonate ester.