Dibenzo diazepine, 11-amino

Dibenzo[c /][l, 3]diazepines 5 or 6 bearing an amino or substituted amino group in position 6 are obtained from biphenyl-2,2 -diamine and 2-methylisothiourea sulfate or ALAAdiisoprop-ylcarbodiimide, respectively.175... 

The reduction of a dinitro ketone to an azo ketone is best achieved with glucose. 2,2 -Dinitrobenzophenone treated with glucose in methanolic sodium hydroxide at 60° afforded 82% of dibenzo[c,f [i 2]diazepin-l 1-one whereas lithium aluminum hydride yielded 24% of bis(o-nitrophenyl)methanol [575], Conversion of aromatic nitro ketones with a nitro group in the ring into amino ketones has been achieved by means of stannous chloride, which reduced 4-chloro-3-nitroacetophenone to 3-amino-4-chloroacetophenone in 91% yield [178]. A more dependable reagent for this purpose proved to be iron which, in acidic medium, reduced m-nitroacetophenone to m-aminoacetophenone in 80% yield and o-nitrobenzophenone to o-aminobenzophenone in 89% yield (stannous chloride was unsuccessful in the latter case) [903]. Iron has also been used for the reduction of o-nitrochalcone, 3-(o-nitrophenyl)-l-phenyl-2-propen-l-one, to 3-(o-aminophenyl)-l-phenyl-2-propen-l-one in 80% yield [555]. 

A more complex structure class with activity at PR is represented by the tetrahydro-1 [H]-dibenzo[fo, /]pyrido[l,2-d][l,4]oxazepine scaffold (62) [77]. This scaffold was modified mainly at the two aromatic systems and the 1-amino functionality. In addition, the central oxazepine ring has been modified to a thiazepine (63), a diazepine and an azepane ring in some examples. Comparable decorations of the whole system delivered active compounds with all these modified central ring systems. The acylation of the 1-amino function, especially with the trifluoroacetyl group (64), resulted in enhanced activity compared to free amino or alkyl substitution. Trifluorothioacetate was essential for agonism of the compounds, while thioureas... 

Formation of the a bond has been achieved by irradiation of acetyl esters of 2,2 -dinitrodiphenyl-carbinols in protic solvents, such as Pr OH, to give dibenzo[c/][l,2]diazepin-l 1-one 5-oxides <9IMI 904-05>. The corresponding dibenzo[c/][l,2]diazepin-l l-ones, 2,2 -dinitrobenzophenones, 2-amino-2 -nitrobenzophenones and iV-hydroxyacridones are also formed in varying amounts the reaction becomes more complex in aprotic solvents. 

Efficient domino approaches to multifunctionalized tricyclic fused pyrroles 59 and dibenzo[h,e][l,4]diazepin-l-ones 60 have been established starting from enam-inones 57 with different substitution patterns and arylglyoxal monohydrates 58. The reaction pathway is controlled by the substituent at the N atom in 57. The domino process can easily be performed by simply mixing 58 and N-amino acid enaminones or 3-(2-aminophenylamino)-5,5-dimethylcyclohex-2-enones 57 in the presence of AcOH under microwave irradiation (Scheme 12.21). The reaction occurs within 12-36 min, with water as the second product. A complete anti diastereoselectivity was achieved within the formation of tricyclic fused pyrrole derivatives [42]. 

Novel 11-perfluoroalkyl-substituted 3,3-dimethyl-ll-hydroxy-2,3,4,5, 10,ll-hexahydro-l//-dibenzo[/>,e][l,4]diazepin-l-ones are prepared via a simple two-step approach. A treatment of 2-peifluoroalkanoylcyclohexane-1,3-diones with ethereal solution of diazomethane gives 5,5-dimethyl-3-methoxy-2-perfluoroalkanoylcyclohex-2-en-l-ones as main products and 6,6-dimethyl-3-hydroxy-3-perfluoroalkyl-2,3,6,7-tetrahydrobenzofuran-4(5//)-ones as by-products. Then, an initial methoxy group vinylogous substitution of enol ethers by one of the o-pheitylenediamine amino groups and an intramolecular cyclization leads to the title compounds in high yields. 

---