1-Tetralone 2,3-diphenyl

As noted earlier, most classical antidepressant agents consist of propylamine derivatives of tricyclic aromatic compounds. The antidepressant molecule tametraline is thus notable in that it is built on a bicyclic nucleus that directly carries the amine substituent. Reaction of 4-phenyl-l-tetralone (18) (obtainable by Friedel-Crafts cyclization of 4,4-diphenyl butyric acid) with methyl amine in the presence of titanium chloride gives the corresponding Schiff base. Reduction by means of sodium borohydride affords the secondary amine as a mixture of cis (21) and trans (20) isomers. The latter is separated to afford the more active antidepressant of the pair, tametraline (20). 

Quallich and Woodall described the first asymmetric synthesis utilizing a catalytic enantioselective reduction of the ketoester 35 with (S)-terahydro-l-methyl-3,3-diphenyl-lH,3W-pyrrolo[l,2-c][l,3.2]oxazaborole (CBS) to give the desired hydroxyester 36 (90% ee). After mesylation, Sn2 displacement with a higher-order cuprate derived from copper cyanide gave the diaryl r-butyl ester 37 with good chirality transfer. Intramolecular Friedel-Crafts cyclization gave the tetralone 31 in 90% ee (Scheme 7). ... 

Several substituted diphenyl tellurium oxides were investigated as catalysts for the aldol condensation between benzaldehyde and tetralone. High catalytic activity is associated with electron-donating substituents in the phenyl rings. Methyl phenyl tellurium oxide had very low catalytic activity1. 

Recent work on the thermal indolization of arylhydrazones has introduced new synthetic possibilities for azaindoles. Kelly et al. refluxed cyclohexanone and deoxybenzoin 2-pyridylhydrazones in diethylene glycol to give 5,6,7,8-tetrahydro-a-carboline (42, R = H) and 2,3-diphenyl-7-azaindole in 70 and 56% yields, respectively, compared with 53 and 12% reported earlier. Similarly, y-carboline 29 was obtained in 95 % yield from cyclohexanone 4-pyTidylhydrazone (lit. 48% ). Several 7-azaindole derivatives were prepared in the same manner. The yields ranged from 5 % for azaindolenine (31) to 88% for 3-phenyl-7-azaindole. 3,3-Dimethyl-7-azaindolenine was obtained in 47 % yield from the isobutyralaldehyde hydrazone. The novel cyclic compounds 40 and 41 were obtained from the 2-pyridylhydrazones of cyclopentanone, a-indanone, and a-tetralone in 67, 95, and 77% yields, respectively. Unfortunately, all attempts to cyclize the acetone, pyruvic acid, and ethyl pyruvate hydrazones were unsuccessful. Also, cyclohexanone and methyl ethyl ketone 5-nitro-2-... 

Cyclic ketones such as 1-decalone321 and tetralone can also be reduced conveniently by this method. Crawford and Nelson330 converted 2,3-diphenyl-2-tetralone into the corresponding alcohol in 93% yield by means of aluminum isopropoxide ... 

C21H1sBrOSi, 3-Bromo-2,2-diphenyl-2-sila-A -1-tetralone, 38B, 646 C21H1eSi, 5-Methyl-5 phenyl-5H-dibenzo[b,fJsilepin, 43B, 834 C2iH2oOSi, 5-Methoxy-5-phenyl-10,11-dihydro-5H-dibenzo[b,f]silepin, 42B, 529... 

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