Prodrugs of excitatory amino acids

A compound of the formula I

• 47
• wherein
• R11 is C(O)YR14 and R12 is hydrogen or fluoro;
• or R11 is hydrogen or fluoro and R12 is C(O)YR14;
• R13 and R14 are, independently, hydrogen, (1-10C) alkyl, (2-4C) alkenyl, (2-4C) alkynyl, or aryl;
• A1 is hydrogen or an α-amino acyl bonded through the carbonyl to form an amine terminus;
• X and Y are independently O or A2;
• A2 is an α-amino acyl bonded through the amine to form a carboxlyate terminus;
• provided when X is O, Y is not O;
• or a pharmaceutically acceptable salt thereof.

A compound of the formula I

• 48
• wherein
• R11 is C(O)YR14 and R12 is hydrogen or fluoro;
• or R11 is hydrogen or fluoro and R12 is C(O)YR14;
• R13 and R14 are, independently, hydrogen, (1-10C) alkyl, (2-4C) alkenyl, (2-4C) alkynyl, or aryl;
• A1 is hydrogen;
• X and Y are, independently, O or A2;
• A2 is an amino acyl bonded through the amine to form a carboxlyate terminus;
• provided when X is O, Y is not O;
• or a pharmaceutically acceptable salt thereof.

A compound of the formula I

• 49
• wherein
• R11is C(O)YR14 and R12 is hydrogen or fluoro;
• or R11is hydrogen or fluoro and R12 is C(O)YR14;
• R13 and R14 are, independently, hydrogen, (1-10C) alkyl, (2-4C) alkenyl, (2-4C) alkynyl, or aryl;
• A1 is hydrogen;
• X and Y are independently O or A2;
• A2 is an α-amino acyl bonded through the amine to form a carboxlyate terminus;
• provided when X is O, Y is not O;
• or a pharmaceutically acceptable salt thereof.