Dibenzodiazepines, synthesis

H-Dibenzo[d,/][l,3]diazepine, 5,7-dihydroxy-synthesis, 7, 605 Dibenzodiazepines synthesis, 7, 605... 

The other way of synthesis of clozapine is from 8-chloro-10,ll-dihydro-5H-dibenzo[b,e]l, 4-diazepin-ll-thione, which is alkylated at the sulfur atom of the dibenzodiazepine ring by 4-nitrobenzylchloride in the presence of potassium fert-butoxide, giving iV-methyl derivative (6.5.8). Reaction of this with A-methylpiperazine gives the desired clozapine (6.5.7) [59]. 

These are the most widely used routes to 1,3-diazepines and provide easy access to the monocyclic system, 1,3- and 2,4-benzodiazepines, and dibenzodiazepines by the reactions of (113)-(116) (and their derivatives) respectively with 1,1-bis-electrophilic reagents. The use of aldehydes produces the rather unstable fully saturated —NHCH2NH— linkage and has been rarely applied to the synthesis of monocyclic systems. (67AHC(8)2l, p. 40) but provides useful syntheses of 1,3-benzodiazepines, e.g. (117) (67AHC(S)2l, p. 43), and 2,4-benzodiazepines, e.g. (118) (68CRV747, p.783). A 5,7-dihydroxy-6fT-dibenzo[[Pg.605]

Scheme 4 Application of ammonia monoarylation in the synthesis of dibenzodiazepines...

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