The condensation of 2'-hydroxy-3-phenylpropiophenone (I) with 1 chloro-2,3-epoxypropane (II) by means of K2CO3 gives 2'-(2,3-epoxypropoxy)-3-phenylpropiophenone (III), which is then treated with 2-methyl-2-aminobutane (IV) in refluxing methanol.
The reaction of ethyl 3-(2-benzylphenyl)-1-methyl-4-oxopiperidine-5-carboxylate (I) with refluxing 5N HCl gives a mixture of 3-(2-benzylphenyl)-1-methyl-4 piperidone (II) and MO-8282. The inter mediate product (II) is cyclized by heating at 100 C with polyphosphoric acid (PPA).