Synthetic, biocatalytic acetylation and anti-tuberculosis activity evaluation studies on (±) -4-alkyl-3,4-dihydro-3-ω-hydroxyalkyl-2<i>H</i>-1 ,3-benzoxazines^¶

Abstract

Five novel (±)-4-alkyl-3,4-dihydro-3-ω-hydroxyalkyl-2<i>H</i>-1,3-benzoxazines have been synthesized by Mannich-type condensation of <i>N</i>-ω-hydroxyalkyl, <i>N-</i>[1-(2-hydroxypheny l)ethyl/propyl]amine and formaldehyde in 55 to 60% yields. Porcine pancreatic lipase in tetrahydrofuran catalyses the acetylation of these benzoxazines in an enantioselective fashion. This perhaps is the first report of the resolution of benzoxazines involving the primary alcoholic group situated far away from the asymmetric center as a remote handle for chiral recognition by porcine pancreatic lipase. The activity of 4-alkyl-3,4-dihydro-3-ω hydroxyalkyl -2<i>H</i>-1,3-benzoxazines and their precursors, <i>i. e. </i>secondary amines and corresponding Schiffs bases have been evaluated for the inhibition of <i>Mycobacterium tuberculosis.</i>