Benz 5,6-dihydro

Benz[a]acridine-3,4-diol, 3,4-dihydro-oxidation, 2, 184-185 Benz[c]acridine-3,4-diol, 3,4-dihydro-oxidation, 2, 185 Benzacri dines synthesis... 

Friedlander synthesis, 2, 444 Benzacridinones, dihydro-von Niementowski synthesis, 2, 447 Benz[6]acridinones, tetrahydro-von Niementowski synthesis, 2, 447 Benzaldehyde... 

Benz-7-azabicyclo[2.2.1]heptenes in isoindole synthesis, 4, 351 Benz[e][l, 2]azaborine, 2-chloro-1,2-dihydro-synthesis, 1, 647... 

Benz[e][ 1,2]azaborine, 1,2-dihydro-2-methyl-halogenation, 1, 656 Benz[6]- 1-azafulvenes dimerization, 4, 309 Benz[c]-2-azafulvenes dimerization, 4, 309 Benzazatropolone X-ray analysis, 7, 494 1 -Benzazepine, N-acetyl-6-hydroxy-bromination, 7, 528... 

Dihydro-l-oxo-3,4-benz-j8-carboline (166) reacted with phosphorus oxychloride and one mole of phosphorus pentachloride at 110° to give l-chloro-3,4-benz-j8-carboline (264). When, however, more than one mole of phosphorus pentachloride was used 265 was obtained, presumably by chlorination of 264. This chlorinating action of phosphorus pentachloride is analogous to that observed when an... 

Ultraviolet spectra of a l,2-dihydro-y-carboline derivative and of a number of quaternary l,2-benz-3,4-dihydro-j8-carbolinium derivatives and of the anhydro-bases derived from them have been... 

Chemicai Name 1 -[ 1 -[4-(4-fluorophenvl)-4-oxobutvl] -4-piperidinyl] -1,3-dihydro-2H-benz-imidazol-2-one... 

Thermolysis of the vinyl azide 26 in xylene yields ethyl 8-(mcthoxymcthyl)-l,8-dihydro-benz[2,3]azepino[4,5- >]indole-2-carboxylate (27) by attack of the vinyl nitrene at the 2-phenyl group.83... 

The dehydrogenation of 2,3-dihydro- and 2,5-dihydro-l//-l-benzazepines to 3//-l-benz-azepincs with heterocyclic enamines in the presence of boron trifluoride diethyl ether complex has been achieved in moderate yields (30-35%).241 In contrast, electrochemical oxidation of 2,5-dihydro-1 H- -benzazepines in buffered acetic acid solution furnishes initially 5//-l-benz-azepines in 35-45% yield.242... 

A detailed study of the dehydrogenation of 10.1 l-dihydro-5//-benz[6,/]azcpinc (47) over metal oxides at 550 C revealed that cobalt(II) oxide, iron(III) oxide and manganese(III) oxide are effective catalysts (yields 30-40%), but formation of 5//-dibenz[7),/]azepinc (48) is accompanied by ring contraction of the dihydro compound to 9-methylacridine and acridine in 3-20 % yield.111 In contrast, tin(IV) oxide, zinc(II) oxide. chromium(III) oxide, cerium(IV) oxide and magnesium oxide arc less-effective catalysts (7-14% yield) but provide pure 5H-dibenz[b,/]azepine. On the basis of these results, optimum conditions (83 88% selectivity 94-98 % yield) for the formation of the dibenzazepine are proposed which employ a K2CO,/ Mn203/Sn02/Mg0 catalyst (1 7 3 10) at 550 C. 

CN 8-Chloro-6,l 1-dihydro-1 l-(4-piperidinylidene)-5//-benz[5,6]cyclohepta[1.2-61pyridine... 

CN 5-(4,5-dihydro-2-phenyl-3//-benz[e]indol-3-yl)-2-hydroxybenzoic acid... 

On reaction of N-thioformylphenylhydrazine 1533 with aldehydes such as benz-aldehyde (or ketones such as acetophenone) in the presence of TCS 14 in benzene 2,3-dihydro-l,3,4-thiadiazoles such as 1535 are formed in high yields via 1534 [65, 66] (Scheme 9.36). 

Exactly such steric repulsion seems to be responsible for the further rearrangements observed with heptaphenylborepin (109 or 114 with R = Ph). The end result of a reasonable, but amazing sequence of pericyclic reactions is 1,2,3,3a,4,5-hexaphenyl-5-bora-3a,4-dihydro-5//-benz[>]in-dene (119), whose generation is initiated with 109 and continues through 116-118 (Scheme 11). The last step, 118-119, is an impressive intramolecu-... 

Carbene complexes have also been prepared by transmetallation reactions. Lithiated azoles react with gold chloride compounds and after protonation or alkylation the corresponding dihydro-azol-ylidene compounds, e.g., (381) or (382), are obtained.22 9-2264 Silver salts of benz-imidazol have also been used to obtain carbene derivatives.2265 Mononuclear gold(I) carbene complexes also form when trimeric gold(I) imidazolyl reacts with ethyl chlorocarbonate or ethyl idodate.2266,2267 The treatment of gold halide complexes with 2-lithiated pyridine followed by protonation or alkylation also yields carbene complexes such as (383).2268 Some of these carbene complexes show luminescent properties.2269-2271... 

Whereas peri methyl substitution does not block dihydrodiol formation in the adjacent ring in the benz[a]anthracene system (38,39), it apparently does so in the chrysene system. 7,8-Dihydro-... 

The DMBA metabolite model compounds which have been examined include the benz[a]anthracene (BA) derivatives, 1,2,3,4-tetrahydro-BA 02, U), 5,6-dihydro-BA U2), and 8,9,10,11-tetrahydro-BA (12,... 

Synonym 20-methylcholanthrene, l,2-dihydro-3-methyl-benz[/]aceanthrylene... 

Diazadienes have been used in organic synthesis for the preparation of various heterocyclic compounds. Alkylation of 1,3-diazadienes 207 and the benz-fused analog 210 at the nitrogen atom by aryl acyl bromides provided the iV-alkyl amidinium bromides 208 and 211, which underwent annulation to the 2,3-dihydro-imidazo[2,l-A]thiazole 209 and imidazo[2,l- ]benzothiazoles 212, respectively (Equations 92 and 93) <2001S741, 2002J(P1)741>. 

Almost complete retention of chirality was achieved in the alkylations of l-propionyl-l,4-dihydro-2//-3,1-benz-oxazines 242 bearing a stereogenic center in the substituent at position 2 (TBDPS = /< rt-butyldiphenylsilyl, KHMDS = potassium hexamethyldisilazide). The alkylations took place with high de s (70-92%) in favor of isomers 243, isolated after chromatographic separation. The allyl-substituted compound 243 (R = allyl) was reduced with LAH to yield the enantiopure (R)-3-methylpent-4-en-l-ol 244 and the N-unsubstituted 3,1-benzoxazine 245 as a 5 1 diastereomeric mixture (Scheme 45) <2000JOC6540>. 

Die Carbonyl-Absorptionen der 2-Oxo-2,3-dihydro-benzidimidazole finden sich in einem wei-ten Bereich (von 1770-1675 cm- x)39, zu den Infrarot-CO-Banden acylierter 2-Hydroxy-benz-imidazole s.668. 

Addiert man Aryl-isocyanate an Triphenyl-phosphan-(2-benzimidazolyl-methylimin) (I), so erhalt man 2-Aminocarbony 1-1 -arylimino-2,3-dihydro-lH-benz-imidazole)(IlI). Die Entstehung der Produkte wird iiber ein Carbodiimid-Zwischenprodukt II interpretiert520. 

Alkyl-3-oxo-2,3-dihydro-<(benzimidazolo[l,2-d]-l,2,4-thiadiazol> eliminieren beim Erhitzen auf 160" Alkyl-isocyanat und Schwefel. Als Zwischenprodukt wird ein 1,2-Dehydro-benz-imidazol formuliert. Ohne Zusatz von Nukleophilen trimerisiert es zu Tribenzimidazo[l,2-a 1, 2 -c /",2"-e]triazin (Schmp. 380°) anwesende Phenole addieren sich zu 2-Ary loxy-benz-imidazolen653 z.B. ... 

Examples of electrophilic substitution (other than protonation) at the heterocyclic ring of benz- and dibenz-azepines appear to be confined to a few Vilsmeier reactions. 8-Chloro-l//-l-benzazepin-2-one with a mixture of DMF and POCl3 yields the 2,8-dichloro aldehyde (106) (72CPB1325). Under similar conditions Ar-mesyl-4,5-dihydro-3//-3-benzazepine formylates at the 1-position (107 R1 = CHO, R2 = H) (71BSF3985). In contrast, (V-mesyl-1,2,4,5-tetrahydro-3/7-3 -benzazepin-1 -one yields a mixture of the 1-chloro dihydro compound (107 R1 = Cl, R2 = H) and the chloro aldehyde (107 R1 = Cl, R2 = CHO). 

Direct electrophilic substitution of benz- and dibenz-azepines remains relatively unexplored. Most substituted benzazepines have been prepared from benzene precursors bearing the desired substituents (74AHC(17)45). The bulk of the reported electrophilic substitutions have been carried out on 5//-dibenz[6,/]azepine (74CRV101), MO calculations on which predict that substitution should occur at the 2- and 4-positions, i.e. para and ortho to the azepine ring nitrogen. These predictions are borne out by Friedel-Crafts alkylation and acylation studies, although it is apparent that a second alkyl group enters at the 8- rather than at the 4-position. Formylation under Vilsmeier conditions yields the 2-aldehyde. As noted earlier (Section 5.16.3.4), however, the 10,11-dihydro system exhibits different behavior and acylates at the benzylic 10,11-positions. Nitration with mixed acids of the... 

Metallation of benz- and dibenz-azepines has been little investigated. 10,11-Dihydro-5 f/-dibenz[6,/]azepine lithiates at the 4-position, this being a convenient route to the 4-carboxylic acid (74CRV101). 

Phosphorus triamide, hexamethyl- (8,9) (1608-26-0) 9-Phenanthrol, 10-chloro-9,10-dihydro-, acetate (8) 9-Phen-anthrenol, 10-chloro-9,10-dihydro-, acetate (9) (1028-73-5) Trimethylsilyl chloride Silane, chlorotrimethyl- (8,9) (75-77-4) Benz[a]anthracene (8,9) (56-55-3)... 

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