Synthesis of N-alkylanthranilamides with a chiral substituent at the nitrogen atom

Novel anthranilamides containing a chiral substituent at the nitrogen atom and different substituents on the benzene ring were prepared from the corresponding isatins in good yields and high enantioselectivities (up to 98%).

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(R)-Ethyl 2-(2,4-dioxo-2H-3,1-benzoxazin-1(4H)-yl)propanoateC13H13NO5Ee ⩾ 98%[α]D20=+15 (c 1 CH2Cl2)Source of chirality: ethyl ester (S)-2-hydroxypropionic acidAbsolute configuration: (R)

Ethyl (R)-N-[2-(azepan-1-ylcarbonyl)phenyl]-2-aminopropionic acidC18H26N2O3Ee ⩾ 98%[α]D20=+9 (c 1.00 CH2Cl2)Source of chirality: ethyl ester (S)-2-hydroxypropionic acidAbsolute configuration: (R)

Ethyl (R)-N-[2-{[((S)-1-phenylethyl)amino]carbonyl}phenyl]-2-aminopropionic acidC20H24N2O3[α]D20=-114 (c 1.00 CH2Cl2)Source of chirality: ethyl ester (S)-2-hydroxypropionic acid and (S)-α-methylbenzylamineAbsolute configuration: (R,S)