Investigation of an Alternative Route to ZD3638 and Cost-Benefit Analysis Comparison of Raw Materials with the Previous Route

A convergent synthesis to ZD3638 was proposed starting with alternative raw materials. A cost-benefit analysis for the new route was performed which demonstrated that significant savings in raw materials costs could be made over the previous linear sequence. The convergent route was then proved in principle by experimental work. LiTMP was shown to be a superior base to LDA in the modified lithiation reaction.