A high yielding synthesis of anthranilate esters from sterically hindered alcohols

A high yielding and operationally simple synthesis of anthranilate esters derived from primary, secondary and tertiary alcohols is reported. Esterification of the alcohol with N-(trifluoroacetyl)anthranilic acid under Steglich conditions, followed by sodium borohydride mediated cleavage of the trifluoroacetyl group affords the anthranilate ester. This new method has application in the synthesis of the ester sidechains of the commonly occurring Delphinium and Aconitum alkaloids and their analogues.