Ugi Reaction with Solid-Supported Carboxylic Acid

3 Ugi Reaction with Solid-Supported Carboxylic Acid 

Representative examples shown in the paper were produced in high yields and purities. 

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Ugi reaction with solid-supported carboxylic acid (Scheme 89) [352] To carbox-ypolystyrene resin (100 mg, 1 mmol/g) were added solutions of 1 m benze-nesulfonamide in THF (1 mb, 10 equiv.), 2 m hydrocinnamaldehyde in CH3OH (0.5 mb, 10 equiv.) and 2 m tert-butyl isocyanide in CH3OH (0.5 mb, 10 equiv.). The suspension was mixed on an ACT babmate at 60 °C [436] for 24 h. The resin was filtered, washed as usual (see previous procedures), and dried. The resin was then treated with a mixture of 40% aqueous methyla-mine and THF 1 1 (v/v) (2 mb) at r. t. for 12 h. The resin was filtered and rinsed with THF (4 mb). The combined filtrates were concentrated to give the crude product (65% purity), which was purified by preparative TbC to give the pure product (19.4 mg, 52% yield). 

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