2.5- benzodiazocines

Pyrrolo[2,1 -c][l, 4]benzodiazepines synthesis, 7, 614 Pyrrolo[l, 6]benzodiazocines synthesis, 7, 515 Pyrrolo[3,4-c]benzopyrazoles reactions, 6, 1034 Pyrrolobenzothiazoles synthesis, 4, 785 Pyrrolo[l, 2-c]benzotriazines synthesis, 4, 240 Pyrrolo[3,4-c]cinnolines synthesis, 4, 240... 

Benzodiazocines 182 and 183 were obtained through a sequence of Ugi-depro-tection-carbonylation/intramolecular amidation using ort/io-iodobenzaldehyde and a bifunctional acid or amine [146] (Fig. 36). This cyclocarbonylation was carefully optimized and succeeded in affording 8-membered lactams, which are typically difficult to obtain, in good yields. 

Benzodiazocines 429 were prepared to be tested as calcium-sensitizing agents (equation 181). A mixture of isomeric lactams was obtained when the Schmidt rearrangement was applied to 427, but only one product 428 was produced using the Beckmann reaction. 

The l,6-dihydro-3,4-benzodiazocine (185) was prepared from the diketone (60JOC1509). Attempted isomerization of (185) to the potentially aromatic 3,4-dihydro compound (186) was unsuccessful. 

Benzodiazocine and dibenzo[Z>,/][ 1,4]diazocine-diones (220) and (218) are obtained by condensation of diethyl succinate and phthalate, respectively, with o-phenylenediamine (69JOC2138). Contrary to an early report, the use of phthaloyl chloride leads to other products and not the tricyclic diazocine. The dibenzo derivative is also formed in the oxidation of diazabiphenylene (219) (78T495). Ring contraction of (218) occurs readily on heating or on treatment with PCI5 or with base. 

Benzodiazocines have attracted much interest as homologs of 1,4-benzodiazepine drugs, and several efficient cyclization methods have been developed. The diamine (289 R = H), available by several routes from the aminobenzophenone, cyclizes slowly in hot pyridine, but treatment of the halide (288) with ammonia leads directly to (292), perhaps by prior... 

R = OMe, R1 = H), whereas reduction with sodium borohydride in methanol in the presence of sodium hydroxide gave 10,11-dimethoxy-l,2,3,4,5,6,7,8-octahydro-2,6-benzodiazocine (92) (59YZ1014). Treatment of 1,3,4,1 lb-tetrahydro-2//-pyrimido[2,l-a]isoquinoline with LAH in boil-... 

A quite different approach to the 1,5-benzodiazocine system begins with 1,3-dipolar cycloaddition of a nitrile oxide and an indolenine (78MI51900). The spiroisoxazoline (303) is converted by irradiation in good yield to the 1,5-benzodiazocinone (304). By using A.AT-alkylenediindoles and bifunctional nitrile oxides, the diazocine ring is incorporated as a repeating unit into a photoconducting polymer. 

---