American Chemical Society
jo400603n_si_001.pdf (2.35 MB)

Concise Synthesis of the Isothiourea Organocatalysts Homobenzotetramisole and Derivatives

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journal contribution
posted on 2013-06-21, 00:00 authored by Beatrice Ranieri, Omar Robles, Daniel Romo
A concise approach to the synthesis of homobenzotetramisole and derivatives is described. Our strategy features a one-pot acylation–cyclization of 2-aminobenzothiazole with α,β-unsaturated acid chlorides to afford annulated pyrimidones. Subsequent Grignard addition followed by acid-promoted dehydration and reduction provides good overall yields of the title compounds in three steps and in quantities up to 10 g. The synthesis employs low-cost and readily available starting materials and enables access to both optical antipodes of these increasingly useful nucleophilic catalysts following chiral separation.