T. J. Thornton, M. Jarman
Sep 18, 1990
Citations
0
Influential Citations
13
Citations
Journal
ChemInform
Abstract
Methyl 2,6-difluoro-4-(pivaloylamino)benzoate (3) and the corresponding4- (tert-butoxycarbonylamino)-analogue 6 have been synthetised by reacting the appropriate 3,5-difluoroaniline derivatives with butyllithium followed by methyl chloroformate. N-(tert-butoxycarbonyl)-2,3-difluoroaniline (9) required thesuper-basic butyllithium/potassium tert-butoxide mixture to convert it into methyl 4-(tert-butoxycarbonylamino)-2,3-difluorobenzoate (14): the 2,5-difluoro-analogue was formed in a similar manner. In all cases the regiocontrol of metallation was directed by fluorine rather than by the amide substituent