Abstract Reaction of 2, 4-dichlorothienopyrimidines and-quinazolines 1 with sodium borohydride gave the corresponding 2-chloro-3, 4-dihydro derivatives 2. Some nucleophilic substitutions of 2b afforded 2-substituted derivatives 3b-7b and reaction of 2g, h with ethyl bromoacetate yielded selectively the corresponding 3-substituted compounds 8g, h which were derived to imidazo [2, 1-b] quinazolin-2-ones 9g, h.