Dolbier HW Solutions 537

Dolbier HW Solutions 537 - This reaction is the f rst step...

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( e ) a -Halo ketones are reactive substrates in nucleophilic substitution reactions. Dibenzylamine is the nucleophile. Because the reaction liberates hydrogen chloride, it is carried out in the presence of added base in this case triethylamine so as to avoid converting the dibenzylamine to its hydro- chloride salt. ( f ) Quaternary ammonium hydroxides undergo Hofmann elimination when they are heated. A point to be considered here concerns the regioselectivity of Hofmann eliminations: it is the less hindered b proton that is removed by the base giving the less substituted alkene. . ( g ) The combination of sodium nitrite and aqueous acid is a nitrosating agent. Secondary alkyl- amines react with nitrosating agents to give N -nitroso amines as the isolated products. 22.35 ( a ) Catalytic hydrogenation reduces nitro groups to amino groups. ( b ) Nitro groups are readily reduced by tin(II) chloride.
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Unformatted text preview: This reaction is the f rst step in a synthesis of the drug lidocaine. 1,3-Dimethyl-2-nitrobenzene CH 3 NO 2 CH 3 2,6-Dimethylaniline CH 3 NH 2 CH 3 1. SnCl 2 , HCl 2. HO 2 H 2 , Pt ethanol CH 3 CH 2 CH 3 CH 2 NO 2 1,2-Diethyl-4-nitrobenzene CH 3 CH 2 CH 3 CH 2 NH 2 3,4-Diethylaniline (93 – 99%) NaNO 2 HCl, H 2 O (CH 3 ) 2 CHNHCH(CH 3 ) 2 Diisopropylamine (CH 3 ) 2 CHNCH(CH 3 ) 2 N O N-Nitrosodiisopropylamine (91%) Elimination to give does not occur CH 3 CH 3 H 3 C 2 H 2 O H 3 C CH 2 H N(CH 3 ) 3 1 OH 2 1 H 3 C CH 2 CH 3 trans-1-Isopropenyl-4-methylcyclohexane (98%) (CH 3 ) 3 N Trimethylamine H 3 C 1-(Dibenzylamino)-2-propanone (87%) CH 3 CCH 2 N(CH 2 C 6 H 5 ) 2 O 1 (C 6 H 5 CH 2 ) 2 NH Dibenzylamine 1-Chloro-2-propanone CH 3 CCH 2 O Cl AMINES 631...
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This note was uploaded on 10/03/2011 for the course CHM 2210 taught by Professor Reynolds during the Fall '01 term at University of Florida.

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