| abstract |
Substituted benzofuran derivatives of formula (I), wherein one of R1? and R2? is hydrogen or halogen and the other is, independently, an amino group or a C2?-C4? alkanoyl amino group; R3? is hydrogen; a linear or branched C1?-C4? alkyl, C1?-C4? alkoxy or C2?-C4? alkoxycarbonyl group; halogen; or phenyl unsubstituted or substituted by a C1?-C4? alkyl group; A is a group -(CH2?)n?-Het wherein Het is an optionally substituted heteromonocyclic or heterobicyclic ring containing one or two nitrogen atoms, and n is zero or an integer of 1 to 3; and the symbol ..... represents a single or double bond; may be prepared by a process comprising reacting a compound of formula (II), in which L is a leaving group and R4? is hydrogen or a carboxy protecting group, with a compound of the formula (III): R'3?-C=C-R'3? to obtain a compound of formula (IV) which is then cyclized to obtain a compound of formula (V) which is reacted with a compound of the formula (VI): H2?N-A. |