Step 1—A flask was charged with tris(dibenzylideneacetone)dipalladium(0) (0.01 eq.), 2-(di-t-butylphosphino)biphenyl (0.04 eq.), sodium t-butoxide (2.4 eq.) and the acid from Example 1 step 8 (1.0 eq.). 1.5 ml toluene (1.0 M) was added to the flask followed by morpholine (1.2 eq.) The reaction was heated to reflux for five hours. The reaction mixture was partitioned between 5% hydrochloric acid and dietheyl ether. The organic layer was washed with distilled water, followed by brine, dried over sodium sulfate and concentrated. The product was purified by preparatory LC-MS to afford 7.8% of the desired product. HRMS calc for [C43H43N3O6S+H] 730.2945 found 730.2945.
