20130345423 | EFFICIENT PEPTIDE COUPLINGS AND THEIR USE IN THE SYNTHESIS AND ISOLATION OF A CYCLOPENTA (G) QUINAZOLINE TRISODIUM SALT - A new method for the synthesis of L-Glutamyl-γ-D-Glutamic acid and its use in the synthesis of (2R)-((4S)-carboxy-4-(4,N-(((6S)-2-(hydroxymethyl)-4-oxo-3,4,7,8-tetrahydro-3H-cyclopenta[g]quinazolin-6-yl)-N-(prop-2-ynyl)amino)benzamido)butanamido)pentanedioic acid, 1 are provided. Also provided is an efficient method for the isolation and purification of the trisodium salt of the abovementioned acid, 2, in a form suitable for long term storage and use in a parenteral dosing form. | 12-26-2013 |