2.5- Dimethyl-3-thienylboronic acid

A simple method for the synthesis of maleic anhydride derivative 165 starting from 2,5-dimethyl-3-thienylboronic acid and commercially available inexpensive mucobromic acid 168 was reported (04IZV2238) (Scheme 52). The starting boronic acid was prepared in good yield from 2,5-dimethyl-3-iodothiophene. 

Other types of HIV-1 protease inhibitors have also been prepared using microwave-promoted Suzuki reaction [37]. The symmetric cyclic sulfamide (3K,4S,5S,6it)-3,6-bis(phenoxymethyl)-2,7-bis[4-(2-thienyl)benzyl]-l,2,7-thi-adiazepane-4,5-diol 1,1-dioxide, for instance, was synthesized via cross-couphng of (3aS,4R,8it,8aS) - 5,7 - bis(4 - bromobenzyl) - 2,2 - dimethyl - 4,8 - bis-(phenoxymethyl) hexahydro [1,3] dioxolo [4,5 - d] [ 1,2,7 ] - thiadiazepine 6,6 - dioxide with 2-thienylboronic acid for 3 min at 45 W (Scheme 19). 

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