This letter describes novel high-yielding solution phase preparations of 1,
4-benzodiazepine-2,5-dione, diketopiperazine, ketopiperazine and dihydroqui
noxalinone libraries via a UDC (Ugi/de-Boc/cyclization) strategy in combina
tion with ethylglyoxalate. The methodology represents a 'three step, one-po
t procedure', employing the Ugi multi-component reaction (MCR), followed by
Boc deprotection and cyclization. (C) 1999 Elsevier Science Ltd. All right
s reserved.