2-Amino-3,5-dimethyl- -bromid

There is also evidence for stable 3,4-adducts from the X-ray analysis of 2-amino-4-ethoxy-3,4-dihydropteridinium bromide, the nucleophilic addition product of 2-aminopteridine hydrobromide and ethanol (69JCS(B)489). The pH values obtained by potentiometric titration of (16) with acid and back-titration with alkali produces a hysteresis loop, indicating an equilibrium between various molecular species such as the anhydrous neutral form and the predominantly hydrated cation. Table 1 illustrates more aspects of this anomaly. 2-Aminop-teridine, paradoxically, is a stronger base than any of its methyl derivatives each dimethyl derivative is a weaker base than either of its parent monomethyl derivatives. Thus the base strengths decrease in the order in which they are expected to increase, with only the 2-amino-4,6,7-trimethylpteridine out of order, being more basic than the 4,7-dimethyl derivative. 

Quinolizinium bromide, 1-acetylamino-Setnmler-Wolff aromatization, 2, 550 Quinolizinium bromide, l-amino-2,3-dimethyl-reactions... 

Diphenylacetonitrile is condensed with 2dimethyl-amino)-2,2-diphenyl valeronitrile. It is then reacted with ethyl magnesium bromide and then hydrolyzed using HCl to give methadone hydrochloride. 

The asymmetric synthesis of amino acids via the addition of allyl and 2,3-dimethyl-2-bulenyl organometallics to ( — )-8-phenylmenthyl A-methoxyiminoacetate (14) was examined12. The results show that both allyl- and 2,3-dimethyl-2-butenylzinc bromide provide good stercocontrol. 

Microwave-assisted Heck reaction of (hetero)aryl bromides with N,N-dimethyl-2-[(2-phenylvinyl)oxy]ethanamine, using Herrmann s palladacycle as a precatalyst, yielded the corresponding /3-(hetero)arylated Heck products in a good EjZ selectivity (Scheme 79) [90]. The a/yd-regioselectivity can be explained by the chelation control in the insertion step. This selectivity is better than 10/90 when no severe steric hindrance is introduced in the (hetero)aryl bromides. The process does not require an inert atmosphere. There is evidence that a Pd(0)/Pd(II)- and not Pd(II)/Pd(IV)-based catalytic cycle is involved. Similarly, other j6-amino-substituted vinyl ethers such as... 

Amino-2-dimethylainino-5-nitrosopyriinidin-4(3/0-one 36 reacts with dimethyl phenacylsulfonium bromides when refluxed in pyridine to give pteridinediones 37 rather than the isomeric 5-7V-oxides 38 < 96H(43)437 >. 

An effect similar to that of cetyltrimethylammonium bromide micelles can be realized through the use of microgels with trimethylamino side-chain function and this may then allow solid supported microgels to be used in a continuous reaction. Evans et al. (1995) have utilized microgels incorporating 2-tetradecyl dimethyl amino/ethyl methacrylate bromide, which solubilizes aryl laurate esters in an aquous solution and catalyses the alkaline hydrolysis. 

The cyclization of 285 proceeded similarly as in the synthesis of 278-281. The N,A-dimethyl-substituted amino ester 285 and cyanogen bromide resulted in 286, and subsequent acid hydrolysis led to the urea ester 287, which was cyclized to l-methylperhydro-2,4-quinazolinedione 288 at elevated temperature [69LA(728)64]. 

Amino-l,2,4-triazole was alkylated with 4-nitrobenzyl bromide by simply refluxing the mixture in isopropanol to give SO in excellent yield. The aminotriazole SO was deaminated with NaNOa in aqueous HCI and the nitro group was reduced with ammonium formate catalyzed by 10% Pd/C to deliver 47 in an improved yield over the route shown in Scheme 17. Diazotization of 47, reduction of the diazonium salt with sodium sulphite and Fischer indolization of the resulting hydrazine with 4-( /, /-dimethylamino)butanol dimethyl acetal was performed in a single step to afford rizatriptan (4) in 45% yield. 

Function of mitochondria is also commonly monitored as an indicator of cellular toxicity. Mitochondrial uptake and retention of the fluorescent dye, rhodamine 123, can be visualized microscopically. Biochemical measurements of mitochondrial function include the ATP-ADP ratio and dehydrogenase activity with MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide), which yields a colored formazan product upon reduction. The dye, neutral red (3-amino-7-dimethyl-amino-2-methylphenazine hydrochloride), targets lysosomes, and its retention is inversely related to cytotoxicity. Commercially available versions of the MTT and neutral red assays have been adapted to microtiter plate formats to provide highly efficient screening assays. Examples of how cell-type-specific functions can be followed as indicators of cell toxicity are included in Table 8.1. 

Methylthiomethyl esters. Carboxylic acids are converted into their methylthiomethyl esters by reaction with t-butyl bromide-dimethyl sulfoxide in the presence of sodium bicarbonate. Methylthiomethyl esters of N-protected amino acids can be obtained in high yield without racemization by this method. ... 

Allyl-methyl-amino)-3-dimethyl-amino- -bromid E8d, 36 [5-NR2 - 3-( =NR) - 3H-1,2,4-dithiazol + Allyl-Br]... 

Ammonium Dimethyl-(5-dimethyl-amino-furfuryliden)- -chlorid (bromid) E14a/3, 235 (5-C1-2-CHO-furan + R2NH)... 

The same 6-amino-5-nitrosouracil is converted by phenacyl bromide-pyridine into a 6-hydroxy-7-phenyllumazines [77H(6)1907]. Condensation with phenacylidenetriphenylphosphoranes and dimethyl acetylenedicar-boxylate gives lumazine derivatives [76CC588 81 H( 15)757 82JHC949] (Scheme 67). 

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