3.5- Dimethyl-4-dimethylaminophenyl

Several aryl N-methylcarbamates have been developed in which a nitrogen-containing side chain is attached to the phenyl group. Typical representatives of this class are 3,5-dimethyl-4-dimethylaminophenyl N-methylcarbamatc (mexacarbate,... 

Methyl-6-aminobenzoselenazole when treated with 3-penten-2-one gave by a simple Doebner-Miller type reaction the 2,7,8-trimethylselenazoloquinoline 43 in 18.6% yield, that is the angular product and not the linearly annelated one was formed. Its structure was confirmed by the coupling constant in proton NMR (71JHC693). Selenazoloquinoline 43 can be converted via the 6-methylpyridium salt in the reaction with 4-dimethylaminobenzaldehyde to 2,6-dimethyl-7,9-bis(l-(4-dimethylaminophenyl)-2-ethenyl)selenazolo[5,4-/]quinolinium iodide 44 (Ar = 4-dimethylaminophenyl). This dye exhibited two absorption maxima between 500 and 600 nm (72MI2). 

The photo-oxidation of the aryl-substituted cycloheptatrienes 7-(/ -methoxy-phenyl)cycloheptatriene and 7-, 1- and 3-(/ -dimethylaminophenyl)cycloheptatrienes to the corresponding radical cations in de-aerated acetonitrile solution was accomplished by electron transfer to the electronically excited acceptors 9,10-dicyanoanthracene, iV-methylquinolinium perchlorate, iV-methylacridinium perchlorate and l,T-dimethyl-4,4-bipyridinium dichloride. In the case of l- p-methoxyphenyl)cycloheptatriene (62), deprotonation of the radical cation occurs successfully, compared with back electron transfer, to give a cycloheptatrienyl radical (63) which undergoes a self-reaction forming a bitropyl. If the photooxidation is done in air-saturated acetonitrile solution containing HBF4 and one of the acceptors, the tropylium cation is formed. Back electron transfer dominates in the / -dimethylaminocycloheptatrienes and the formation of the cycloheptatrienyl radical is prevented. 

Quinoxaline-2,3-dione is converted into 2,3-dichloroquinoxaline by phosphoryl chloride142 or phosphorus pentachloride.143 2,3-Dibromo-quinoxaline is similarly obtained using phosphoryl bromide in dimethyl-aniline.144 Quinoxalin-2-one undergoes ring contraction to 2-methyl-benzimidazole (134) with hydrazine145 however, quinoxaline-2,3-dione gives 3-hydrazino-2-quinoxalinone.145 Quinoxalin-2-one yields a 3-p-dimethylaminophenyl derivative with 7V,N-dimethylaniline (in AcOH, with NH4N03), and a 3-(indol-3-yl) derivative with indole.146... 

Dimethylaminophenyl 4-Methoxyphenyl Tellurium Bromide Succinimide1 1.42 g (4 mmol) of 4-dimethyl-aminophenyl 4-methoxyphenyl tellurium are dissolved in 50 ml of benzene and 0.72 g (4 mmol) of A -bromosuccinimidc dissolved in 10 ml of benzene are added. The mixture is stirred for 3 h, the yellow crystalline precipitate is filtered off, washed with benzene, and dried under reduced pressure yield 2.1 g (100%) m.p. 160°... 

Ethoxy-7-methoxy-2-methyl-l-benzotellurinium fluorosulfate reacted with 4-dimethyl-aminobenzaldehyde to form 2-[2-(4-dimethylaminophenyl)-ethenyl]-4-ethoxy-7-methoxy-1-benzolellurinium fluorosulfate1. 

A combined system of the BINAP-Ir complex and bis(o-dimethylaminophenyl)phenylphosphine or (o-dimethyl-aminophenyl)diphenylphosphine catalyzes hydrogenation of benzylideneacetone and cyclic aromatic ketones with modest to high enantioselectivities (eq 25). 

The 3-methylimino 1,2-benzisothiazole 150, which in solution is in equilibrium with 2-methyl benzisothiazole 151, reacted with concentrated tetrafluoric and nitric acids to produce 3-benzensulfonylazo-2-methyl-l,2-benzisothiazolium tetrafluo-roborate 152 in quantitative yield. This salt 152 was treated with A A -dimethyl-aniline to give 2-methyl-3-[4-(l-dimethylaminophenyl)azo]-l,2-benzisothiazolium perchlorate 153 in 63% yield (71LA46, Scheme 51). 

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