1/7-1,4-Diazepine 2,3-dihydro-2,3-diphenyl

Thieno[ 1,2,3]diazaborines, dihydro-bromination, 1, 656 deuteration, 1, 658 iodination, 1, 656 nitration, 1, 656 nucleophilic substitution copper-promoted, 1, 658 Thienodiazepines synthesis, 7, 595 Thieno[ 1,2]diazepines synthesis, 7, 598 Thieno[2,3-d][l, 2]diazepines synthesis, 4, 749 Thieno[3,2-d][l,2]diazepines synthesis, 4, 749 Thieno[ 1,3]diazepines synthesis, 7, 607 Thieno[ 1,4]diazepinones as anticonvulsants, 1, 170 Thieno[3,4-d][l,3]dioxol-2-one, 4,6-diphenyl-... 

Irradiation of 4-methyl-5,7-diphenyl-3//-l,2-diazepine at — 70°C gives 5-methyl-l,6-diphenyl-4,6a-dihydro[l,2]diazeto[l,4-a]pyrrole in 83% yield.105... 

Eine ungewohnliche Dimerisierung ist bei der Reduktion von 2,3-Dihydro-6-phenyl-1,4-diazepin-Hydropcrchlorat zu beobachten. Es entsteht - unter Verlust von 1,2-Diami-no-athan - in hoher Ausbeute 2,9-Diphenyl- (R = H) bzw. 7-Methyl-2,9-diphenyl-6,7-dihydro-5H- (pyrrolo-[l,2-d]-l,4-diazepin) (R = CH3) 2... 

The reaction of succinic acid anhydride 111 with 2-methyl-2,4-diphenyl-2,3-dihydroli/-benzo[Z ][l,4]diazepine 112 in toluene in the presence of potassium carbonate leads to 4-(2-methyl-2,4-diphenyl-2,5-dihydro-l/f-l,5-benzodiazepin-5-yl)-4-oxobutanoic acid 113 in 70% yield [110], while its treatment with 2,4-diphenyl-2,3-dihydro-l//-l,5-benzodiazepine 104 follows with chalcone elimination and yields 3-(benzimidazol-2-yl)propionic acid 114 [115] (Scheme 4.36). 

Flash pyrolysis of 5,7-diphenyl-2,3-dihydro-1/7-1,4-diazepine (34, R = H) at 700°C in a vacuum afforded 2-phenylpyrazine (35) in 21% yield, after separation from a pyrimidine the methyl substrate (34, R = Me) also gave a small yield of the same product (35) and 6-phenyl-2,3-dihydro-17/-l,4-diazcpine gave some unsubstituted pyrazine.176,1698... 

The stereochemical outcome of the rearrangements of At,iV-dibenzylidene-l,2-cyclopropanedi-amines to 2,3-dihydro-2,3-diphenyl-l,4-diazepines parallels the rearrangement of 1,2-divinylcy-clopropanes. Substrates derived from cis-1,2-cyclopropanediamines with E,E geometry at the double bonds and aromatic aldehydes rearrange at room temperature to cis-diazepines 18. The trans-substrates require temperatures > 90 °C because of primary epimerization to the ra-sub-strates via a diradical intermediate766,1053. 

A novel ring contraction of 4,6-dihydro-3,7-diphenyl-5-(4-methylphenylsulfonyl)-l,2,5-triazepine (135, X = NTs) occurs under specific, monochlorination conditions <85H(23)1675>. An excess of chlorine or sulfuryl chloride in dichloromethane leads to the dichlorotriazepine derivative (136), but with one equivalent of sulfuryl chloride in dichloromethane, or one equivalent of NBS in carbon tetrachloride, formation of the dichlorotriazepine is minimized and up to 86% of4-tosylamino-3,6-diphenylpyridazine (137) is produced (Scheme 106). In polar solvents other, 5-membered ring, products are produced. Thermal decomposition of a series of 3,6-diaryl-2,7-dihydro-l,4,5-thia-diazepines (135, X = S) gave 3,6-disubstituted pyridazines in high yield <89BCJ2608>. 

The condensation of a-bromoacetophenone azines with dimethyl malonate in the presence of NaOMe affords 5,5-bis(methoxycarbonyl)-3,7-diaryl-5,6-dihydro-4//-l,2-diazepines <77BCJ2153, 92M1904-01 > this method has been extended to reactions involving malononitrile and ethyl cyano-acetate in the presence of NaOEt to give similar 5,6-dihydro-3,7-diphenyl-4//-l,2-diazepines in 70 and 75% yields, respectively <86JHC557>. 

Dihydro-l,4-diazepines will perform 1,3-dipolar cycloaddition reactions with nitrile oxides and nitrile imines but it is only the imine bonds in the diazepine that react. Thus, 2,3-dihydro-5,7-diphenyl-1-methyl-17/-1,4-diazepine (64 R = Me) only gave mono adducts (65) with arylnitrile... 

C28H16N2, (3-Pyrida-3-(2,6))(6-benza-6-(1,4 2,5))(9-pyrida-9-(2,6))-spiro[5.5]undecaphane-l,4,7,l0-tetraene, 43B, 384 C24H21N3O3, 3aa,40,8/3-3a,4-Dihydro-3-oxo-2,3a-diphenyl-4,8-etheno-3H-pyrazolo[1,5-c](1,3)diazepine-7(8H)-carboxylic acid ethyl ester, 46B, 300... 

Ring contraction. 5,6-Dihydro-4-oximino-3,7-diphenyl-4H-l,2-diazepine refluxed 2.5 hrs. with aq. 10%-NaOH 2,3-diphenylcyclopent-2-en-l-one oxime. Y 70%. N. A. Evans, R.B. Johns, and K.R. Markham, Australian J. Ghem. 20, 713 (1967). 

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