3- Benzyl-4-methylamino

Under these conditions, the even less reactive 5-aminomethyl-3-benzyl-4-methylamino-l,2,3-triazole gave some of the 5-formamidomethyl analog, but no 9-benzyl-3,6-dihydro-3-methyl-8-azapurine (69). An attempt to cyclize this formyl derivative by heating at 200°C caused it to undergo a Dimroth retrogression to 4-benzylamino-5-formamidomethyl-3-methyl-1,2,3-triazole other attempts to close the ring also failed.64... 

Preparation by hydrogenolysis of 2-(benzyl-methylamino)-1 -(2-hydroxy-5-methylphenyl) ethanone with hydrogen in the presence of Pd/C as catalyst [4749]. 

I, 4- and 3,4-Dihydroquinazolines are tautomeric but any attempts to prepare the former w ithout a 1-substituent have led to the latter. The greater stability to proto tropic change of 1,2-dihydronaphthalene over 1,4-dihydronaphthalene is also found in 3,4-dihydroquinazoline. Earlier claims to the preparation of l,4-dihydroquinazolines ° were erroneous and based on incomplete experimental data. The first 1,4-dihydroquinazoline was prepared as recently as 1961. 1-Methyl and l-benzyl-l,4-dihydroquinazolines were obtained from o-methylamino-and o-benzylamino-benzylamines (42) by formylation and ring closure. Attempts to remove the benzyl group gave 3,4-dihydroquinazoline. These 1,4-dihydro compounds are susceptible to oxidation, and attempts made to prepare 1,2-dimethyl-1,4-dihydroquinazoline from o-... 

Chemical Name 2,6-Oimethyl-4-(3-nitrophenyl)-3-methoxycarbonyl-1 /4-dihydropyridine-5-carboxylic acld-2(N-benzyl-N-methylamino)ethyl ester hydrochloride... 

A mixture of 4.98 g of acetoacetic acid N-benzyl-N-methylaminoethyl ester, 2.3 g of aminocrotonic acid methyl ester, and 3 g of m-nitrobenzaldehyde was stirred for 6 hours at 100°C in an oil bath. The reaction mixture was subjected to a silica gel column chromatography (diameter 4 cm and height 25 cm) and then eluted with a 20 1 mixture of chloroform and acetone. The effluent containing the subject product was concentrated and checked by thin layer chromatography. The powdery product thus obtained was dissolved in acetone and after adjusting the solution with an ethanol solution saturated with hydrogen chloride to pH 1 -2, the solution was concentrated to provide 2 g of 2,6-dimethyl-4-(3 -nitrophenyl)-1,4-dihydropyridlne-3,5-dicarboxylic acid 3-methylester-5- -(N-benzyl-N-methylamino)ethyl ester hydrochloride. The product thus obtained was then crystallized from an acetone mixture, melting point 136°Cto 140°C (decomposed). 

The method is very useful for the synthesis of physiologically interesting a-mcthylamino acids, e.g., methyl dopa from the 3,4-dimethoxybenzyl derivative. The excellent stereoselection achieved in the process, however, is caused by the preferential crystallization of one pure diastereomerfrom the equilibrium mixture formed in the reversible Strecker reaction. Thus, the pure diastcrcomers with benzyl substituents, dissolved in chloroform or acetonitrile, give equilibrium mixtures of both diastereomers in a ratio of about 7 347. This effect has also been found for other s-methylamino nitriles of quite different structure49. If the amino nitrile (R1 = Bn) is synthesized in acetonitrile solution, the diastereomers do not crystallize while immediate hydrolysis indicates a ratio of the diastereomeric amino nitriles (S)I(R) of 86 1447. 

Ainino t-(methylamino-hydroxy-methyl)- 597 1-Anilinocarbonyl- 136 l-Benzyl-2-aminocarbonyl- 600... 

Benzyl-3-methylbenzo[g]pteridine-2,4(3//,10/i)-dione (532) gave, among other products, l-benzyl-3-methylamino-2(177)-quinoxalinone (533) [Me-(PhCH2)NOH, Me2NCHO, 20°C, light exclusion, 9 h 15% after separation ... 

J ,3J ,4J ,5J )-2,5-bis(benzyloxy)-3,4-dihydroxy-Nd -bis (lS)-2-methyl-l-[(methylamino)carbonyl]propyl hexanediamide is a C2-symmetric HIV-1 protease inhibitor [29]. Derivatization in the para positions of the benzyl-oxy groups via microwave-assisted Stille reaction on the corresponding di-brominated inhibitor smoothly yielded the desired heteroarylated derivatives (Scheme 10). Interestingly, the 1,3-thiazole derivative showed a higher antiviral activity on the wild type virus than the lead compound. The activity remained at the same level in the presence of seriun. Unfortimately, a low activity was observed on mutants. 

This method was used in a large-scale synthesis of l-benzyl-3-methylamino-4-methylpiperidine.95... 

Benzylidenehydrazino-2( 1 //)-quinoxalinone l-Benzyl-3-methylamino-2(l//)-quinoxalinone l-Benzyl-6-methyl-3-morpholino-2(l//)-... 

Reduction of 3-benzyl-8-chloro-4-oxo-4//-pyrido[l,2- ]pyrimidine-2-carboxylate <2004W004/064741> and 2-methyl-4-oxo-4//-pyrido[l,2-tf]pyrimidine-3-carboxylate <2003T4123> with DIBAL-H afforded 2- and 3-formyl derivatives, respectively. Reduction of /V-(4-fluorobenzyl)-3-hydroxy-8-[methoxy(methyl)amino]-4-oxo-6,7,8,9-tetra-hydro-4//-pyrido[l,2- ]pyrimidine-2-carboxamide with Zn-dust in aqueous AcOH afforded the 8-methylamino derivative, which was acylated with AcOH in the presence of Hiinig s base, HOBt, and l-(3-dimethylaminopro-pyl)-3-ethylcarbodiimide-HCl <2004W004/058756>. 3-(Perhydropyrido[l,2- ]pyrimidin-2-yl)propylamine was obtained by catalytic hydrogenation of 2-(perhydropyrido[l,2- ]pyrimidin-2-yl)propionitrile over a Pt02 catalyst <2003FRP1275647>. 

If the quaternary nitrogen is a member of a ring, the ring is cleaved. 3-Benzyl-2-phenyl-A, A -dimethylpyrrolidinium chloride was cleaved by hydrogenation over Raney nickel at 20-25° almost quantitatively to 2-benzyl-4-dimethylamino-l-phenylbutane [722]. Reduction of methylpyridinium iodide (and its methyl homologs) with sodium aluminum hydride gave 24-89% yields of 5-methylamino-l,3-pentadiene (and its methyl homologs) in addition to A -methyl dihydro- and tetrahydropyridine [448]. 

A second way is by alkylation of 10,ll-dihydro-5H-dibenz[b,f]azepine with 3-(A-benzyl-A-methylamino)propyl chloride in the presence of sodium amide and the subsequent debenzylation of the resulting product (7.1.14) by hydrogenation using a palladium catalyst [21,22]. 

Figure 1. First order plots based on hydrogen evolution for the oxidative dehydrogenation of ethanolamine (EA), 2-(2-aminoethylamino)ethanol (AEAE), 3-amino-1-propanol (AP), 2-(methylamino)ethanol (MAE) and benzyl alcohol (BA) over chromia-promoted copper.

The phosphine oxide (-)-(5 )-[2-(dimethylamino)ethyl]methyloxophenylphosphorane85 was treated with butyllithium or LDA to give, via directed lithiation, the methylene-deprotonated compound regioselectively. Alkylation with bromomethylbenzene gave (S)-[l-benzyl-2-(di-methylamino)ethyl]methyloxophenylphosphorane with low diastereoselectivity (d.r. 55 45)86. 

Methylamino- und 4-Benzylamino-indol lagem sich beim Erhitzen mit 4-Methyl-benzol-sulfonsaure-Hydrat unter intermediarer Ringoffnung zu 4-Amino-1-methyl- (75%) bzw. 4-Amino-l-benzyl-indol (90%) um4 ... 

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