A modification of the classical Camps cyclization is described.
A series of substituted 4-quinolone derivatives is prepared via
trimethylsilyl trifluoromethanesulfonate/triethylamine induced
cyclocondensation of substituted ortho-amidoacetophenones.
The process shows a broad substrate scope and allows selective preparation
of 2-aryl- and 2-alkyl-substituted 4-quinolones. Enantiopure
starting materials react without loss of optical purity using the
modified conditions. Subsequent transformations of the products
involving preparation of a 4-quinolyl nonaflate and O-selective
methylation are also described.
Camps cyclization - 4-quinolones - cyclocondensation -
ortho-amidoacetophenones - nonaflates
