An expeditious synthesis of highly substituted 1,4-diazepines and their rearrangement into 2H-1,3-oxazines
Abstract
3-lminoprop-1-enylamines 1 react successively with diethylgermanium dichloride and diethyl oxomalonate to afford 1,3-dihydro-1,4-diazepin-2-ones 4; the crystal structure of 4a has been determined and its thermal behaviour leading to 2H-1,3-oxazines 5 studied.