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 d emonstrated that significant savings in raw materials costs could be made o ver the previous linear sequence. The convergent route was then proved in p rinciple by experimental work. LiTMP was shown to be a superior base to LDA in the modified lithiation reaction.