Benzylamine 4-hydroxy

Recently, it was found that the addition of benzylamine to 2-(5//)-furano-3-ylmethanesulfonate 280 (X = O—SOaMe) in methanol afforded a 7 1 mixture of the trans- and cw-methyl-A-benzyl-2-hydroxymethylaziridine-2-carboxylates 281 and 282, respectively (00TL3061). Treatment of 281 with benzyl alcohol in the presence of BF3 OEta furnished, after hydrolysis, rac-cw-amino-a-hydroxy-/3-butyrolactone 284 (Scheme 74). 

The respective amide was prepared from 7-substituted 5-oxo-2,3-dihydro-5//-pyrido[l,2,3-de]-l,4-benzoxazine-6-carboxylic acids via acid chlorides with different benzylamines (00M1P3). 6-Carboxamides were N-benzylated, and a side-chain phenolic hydroxy group was O-alkylated. 7-Aryl-5-oxo-2,3-dihydro-5//-pyrido[l, 2,3-r/e]-1,4-benzoxazine-6-carboxylic acid was obtained from the ethyl ester by alkalic hydrolysis. 

Theophylline is reacted first with 1 -bromo-3-chloropropanetogivechloropropyl theophylline, then with benzylamine to give benzylaminopropyltheophylline. That is reacted with 3,5-di-hydroxy-CJ-bromoacetophenone to give the starting material. 

As previously described, die main intermediates generated from die initial reaction between ortho reactive sites on novolac resins and HMTA are hydroxy-benzylamines and benzoxazines.44 Triazines, diamines, and, in die presence of trace amounts of water, benzyl alcohols and ethers also form (Fig. 7.16). Similar intermediates, with the exception of benzoxazines, are also observed when para sites react with HMTA. 

Dioxo-4,8-diphenyl-l,3,5,7-tetraaza-bicyclof3.3.0]octan laBt sich durch Lithium-alanat in5-Hydroxy-3- phenyl-1,2,4- triazolidin (14% d.Th.), N-Methyl- benzylamin auf-spalten4 ... 

The advantages of the one-step silylation-amination of hydroxy-N-heterocycles are demonstrated by the amination of 2-methylpyrido[3,4-d]pyrimidin-4-one 261. Whereas silylation-amination of 261 with three equivalents of benzylamine-... 

In contrast with the hitherto described silylation-aminations of six-membered heterocycles, silylation-amination of five-membered hydroxy-N-heterocycles such as benzoxazol-2-one 289 with excess benzylamine and HMDS 2, to give 2-benzyla-minobenzoxazole, fails, because of the equilibrium between 2-trimethylsilyloxy-... 

Fenton and co-workers observed the hydrolysis of bis- and tris-nitrophenyl phosphate with the zinc complex of the pentadentate N302 ligand V,V - (salicylideneimino)-ethyl -2-hydroxy-5-nitro-benzylamine.890... 

B. Methyl 2-(benzylamino)methyl-3-hydroxybutanoate. A dried, 2-L, onenecked, round-bottomed flask, equipped with a magnetic stirring bar, is charged with 68.7 g (0.53 mol) of methyl 3-hydroxy-2-methylenebutanoate and 800 mL of anhydrous methanol. After the addition of 57.7 mL (0.53 mol) of benzylamine (Note 1), the mixture is stirred at room temperature for 48 hr (Note 3). The methanol is removed under reduced pressure to leave 125.6 g (100%) of the amino ester as a clear oil, essentially pure by 1H NMR analysis (Note 4). 

In a subsequent study, Schnitzer and Spiteller [15] hydrolyzed each fraction with 2 M H2S04. After neutralization of the soluble materials, the latter were reduced with NaBH4 and then acetylated. The resulting acetates were analyzed by capillary gas chromatography/mass spectrometry, and identified by comparing their mass spectra with those of reference compounds of known structures and with literature data. Eighteen N-heterocyclics were identified. These compounds induded hydroxy-and oxy-indoles, quinolines, isoquinolines, aminobenzofurans, piperidines, pyrro-lines, and pyrrolidines. In addition, a number of benzylamines and nitriles were also identified. It is noteworthy that the N heterocyclics were isolated and identified without the use of pyrolysis. 

Synthesis of a C(8)-C(18) segment of the larger fragment of lb using the same basic strategy is depicted in Scheme 25. Here, hydroxy ketone 176 was subjected to syn-selective (dr of crude product=90 10) reductive amination [42] with sodium cyanoborohydride and benzylamine followed by tetrahydro-oxazine formation using aqueous formaldehyde. The resulting heterocycle 182 was then converted to unsaturated ester 184 by successive desilylation, oxidation, and entirely (Z)-selective Horner-Wadsworth-Emmons olefination. Re-... 

Derivatives of the 2,5-diazabicyclo[2.2.1]heptaine ring system (bridged piperazines) have been prepared from 4-hydroxyprolines. In a multistep transformation from tra j-4-hydroxy-L-proline (the last step was cyclization with benzylamine) a mixture of diastereoisomers 71 was obtained and separated [92H(34)241]. In a similar manner, the methyl and oxo analogs were obtained [67AJC1493 92H(34)679]. The commercially available N-... 

N-Benzyl-l-oxophenalene. A mixture of 9-hydroxy-l-oxophenalene (0.98 g, 0.005 mol) and benzylamine (10 mL) was refluxed for 10 h in argon. After cooling, yellow crystals were formed and were separated by filtration. The crude product was purified by column chromatography on AljOj with CHCI3 to give a yellow solid (1.3 g, 92%) and further purification was done by crystallization from hexane. 

For other chiral reagents and application of this method to other classes of compounds, such as a-amino esters, a-hydroxy esters, amino alcohols, chiral a-deuterated benzylamine, phosphorus compounds, and the use of nuclei other than hydrogen (l3C, 19F), see reference 186 and Section D.4.1. 

Following the same procedure, formation of the imine 6D and subsequent deprotonation with two equivalents of butyllithium followed by alkylation, either enantiomer of the a-substituted benzylamines could he obtained with nearly complete stereocontrol. Unfortunately only poor yields are obtained51,52,53. The (-)-(15,25, 55)-2-hydroxy-3-pinanone derived from ( + )-a-pinene resulted in the formation of the R-configurated benzylamines, conversely the ( + )-2-hy-droxy-3-pinanone derivative led to the (S )-benzylamine product. It has been shown that the high stereocontrol occurs within the alkylation step. The chiral auxiliary can be recovered without racemization from the oxime with aqueous titanium(III) chloride. 

Allylische Silane gehen mit Benzylamin und waBrigem Formaldehyd in Gegenwart von Trifluoressigsaure eine Cyclokondensation ein unter Bildung von z. B. l-Benzyl-4-hydroxy-piperidin, 2-Renzyl-4a-hydroxy-cis-decahydro-isochinolin bzw. l-Benzyl-4-hydroxy-4-( 2-hydroxy-ethyl)-piperidin2. 

An attempt to utilize this conversion of amines into aldehydes in an isoquinoline synthesis was not successful.439 Instead, reaction between 2-(3,4-dimethoxyphenyl)ethylamine and isatin afforded only the spiro compound 150.439 Reaction between isatin and 2-(3-hydroxy-4-methoxyphenyl)ethylamine gave a mixture of two spiro compounds, while a reaction of isatin, this amine, and benzylamine gave 6-hydroxy-7-methoxy-l-phenyl-1,2,3,4-tetrahydroisoquinoline.439... 

In other reports, /i-cyclodcxtrins have been used to induce asymmetry in borohydride reduction of ketones,166 a diastereoselective reduction has been controlled167 by a real lyltricarbonyl iron lactone tether , a phosphinamide has been combined with a dioxaborolidine unit as an activated, directed catalyst for ketone reduction,168 reductive amination using benzylamine-cyanoborohydride converts 3-hydroxy ketones into syn-1,3-amino alcohols,169 l-(3,4-dimethoxyphenyl)-2-(2-methoxyphenoxy)propan-l-one has been reduced diastereoselectively,170 and production of chiral alcohols via (i) Itsuno-Corey and Brown procedures171 and (ii) lithium aluminium hydride modified by chiral nucleophiles172 has been reviewed. 

Concentrations range from 0.01 to 2 % in the modifier (typically 0.005 % in the complete mobile phase). Hydroxy-benzoic acids (2), polycarboxylic acids (3), benzylamines (4), PTH-amino acids (5) and many other families of polar solutes only elute when an appropriate additive is present in the mobile phase. 

Feeding experiments with doubly labeled 3-hydroxy-4-[14C]methoxy-A-meth-yl-(f -[3H]- and -(5)-[3H]A,-benzylamines in King Alfred daffodils produced oduline (186) with high (82-85%) tritium retention (139). This observation suggested that the incorporation of A-methylisovanillamine into 186 occurred by a nonstereospecific process in which hydrogen removal from the benzylic position was governed by a kinetic isotope effect. 

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