Model OM9925E (2450 MHz, 800 W), was used. The purity of the compounds was checked on silica gel coated
Al plates (Merck).
Preparation of Benzodiazepine Derivatives (Table 1). A. Solutions of compounds 2/4a,b/6a-c/8
(0.01 mol) and o-phenylenediamine 1 (0.01 mol) in xylene (10 ml)/glacial acetic acid + ethanol
(1:2)/hydrochloric acid (5.5 N)/glacial acetic acid + ethanol (1:2), respectively, were refluxed under constant
stirring for 4-6 h. The progress of the reaction was monitored on TLC. The reaction mixtures were cooled and
the products that separated were filtered off, dried and recrystallized from ethanol.
B. Diamine 1 (0.01 mol) was added to solutions of compounds 2/4a,b/6a-c/8 (0.01 mol) in xylene
(5-10 ml) taken in an Erlenmeyer flask, and the contents were subjected to MW1 for an appropriate time and
worked up as described in method A.
C. Alumina was added to a solution of diamine 1 and compound 2/4a,b/6a-c/8 in ethanol. The reaction
mixture was dried and placed in the alumina bath inside the microwave oven at 560 W for 40-60 s. The progress
of reaction was monitored by TLC at intervals of 10 s. On completion of the reaction, the reaction mixture was
cooled to room temperature, the product was extracted with ethanol (3 × 10 ml), and the solvent was removed
under reduced pressure to yield the corresponding title compounds.
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