W. Aelterman et al., Conversion of the laboratory synthetic route of the N-aryl-2-benzothiazolamine R116010 to a manufacturing method, ORG PROC R, 5(5), 2001, pp. 467-471
A facile and large-scale preparation of the antitumor agent R116010 has bee
n developed. The new synthetic process requires four steps: (i) Friedel-Cra
fts reaction of N-phenyl-2-benzothiazolamine with 2-chloropropionyl chlorid
e, (ii) conversion of the alpha -chloroketone into the corresponding alpha-
(dimethylamino)ketone and resolution of the latter, (iii) reduction of the
chiral aminoketone with resultant formation of the beta -amino alcohol and
finally (iv) conversion of the amino alcohol into the beta -aminoiniidazole
R116010. The key strategic improvement is the crystallization-induced dias
tereomeric dynamic resolution of the aminoketone, leading to the chiral ket
one in 90% yield and 90% enantiomeric purity. This new process improves the
overall yield from 0.26 to 18.8% without tedious chromatographic separatio
ns and hazardous reaction conditions.