5H-2,3-Benzodiazepines

H-2,3-Benzodiazepine, 3,4-dihydro-synthesis, 7, 596, 599 5H-2,3-Benzodiazepine, 4-phenyI-acylation, 7, 602 photochemical reactions, 7, 600 5 H-2,3 - Benzodiazepine, 1,2,3,4-tetrahydro-synthesis, 7, 596... 

A mixture of 38.6 g (0.1 mol) of 3,4,3, 4 -tetramethoxy-6-(a-acetopropyl)-benzophenone, 5.5 g (0.11 mol) of 100% hydrazine hydrate or 3.52 g (0.11 mol) of hydrazine, and 500 ml of absolute ethanol is boiled for 5 hours. After adding 100 ml of benzene, 400 ml of solvent mixture Is distilled off from the reaction mixture by slow boiling for 3 hours. After cooling for 8 hours, 19 g of 5H-2,3-benzodiazepine derivative are separated from the residue as small, white crystals. The melting point is 133°C to 1 36°C (after recrystallizing from absolute ethanol, 136°C). 

Anderson, B.A., Hansen, M.M., Harkness, A.R. et al. (1995) Application of a practical biocatalytic reduction to an enantioselective synthesis of the 5H-2,3-benzodiazepine LY300164. Journal of the American Chemical Society, 117, 12358-12359. 

H- 1,2-Benzodiazepines (12) (75JCS(Pl)102,78CPB1890) and 1//-2,3-benzodiazepines (77) (73JCS(P1)2543, 80JCS(P1)1718) on treatment with bases in protic solvents undergo proton shifts to give their more stable isomers 117-1,2- (42) and 5H-2,3-benzodiazepines (76) respectively. 

H-2,3-Benzodiazepin 1,4-Dihydr-oxy-8-nitro- E9d, 358 (1,3-Dioxo - 3,4-H2 — 1 H-2-benzo-pyran/N2H4)... 

Alkyl-l-aryl-5H-2,3-benzodiazepines (LIX) are reduced in acidic solution in a four-electron reduction [153, 345] in dilute hydrochloric acid l-aryl-3-alkylisoquinoline is formed [153]. In DMF, LIX is reduced with 2F/mol to its 1,2-dihydro derivative. 

Startg. m., glacial acetic acid, and coned. HCl stirred and heated to 90-95 and an additional 15 min. at this temp., then 98%-hydrazine hydrate added dropwise at 60 73 -> 5-ethyl-l-(3,4-dimethoxyphenyl)-7,8-dimethoxy-4-methyl-5H-2,3-benzodiazepine. Y 78-82%. J. Korosi and T. Lang, B. 107, 3883 (1974). 

Mesity lenesu Ifony loxy lamine 3,4-Dihydro-5H-2,3-benzodiazepines... 

A soln. of 0-mesitylenesulfonylhydroxylamine in methylene chloride added to a soln. of the startg. m. in the same solvent, stirred 5 min., then aq. 5%-NaOH added 3-phenyl-3,4-dihydro-5H-2,3-benzodiazepine. Y 57%. F. e. s. Y. Tamura et al., Synthesis 1973, 159. 

---