3-Amino-1-benzyloxy

Amino-benzyloxy-methylen)- -methylester-nitril E15/2, 1804 [(NC)2CH-COOR + R-OH] (Amino-phenoxy-methylen)- -ethylester-nitril E15/2, 1762 (NC-CH2-COOR + R-OCN)... 

Benzylthio or 2-benzyloxy derivatives of A-2-thiazoline-5-one (224) are readily opened by amines to give the amide derivatives (225) (Scheme 115) (459. 471). Compound 225 can be cyclized thermally to the corresponding thiohydantoins (459). Similarly, treatment of 4-substituted-2-phenylthiazol-5(4H)-ones (226) with amino acids, peptides, or hydrazine affords the corresponding Nfcti-thiobenzamidoacetylated derivatives (227) (Scheme 116) (455). 

Uracil, 6-amino-1-benzyl-5-nitroso-2-thio-syn esis, 3, 131 Uracil, 6-amino-2-thio-synthesis, 3, 115 Uracil, 1-benzyl-syn esis, 3, 109 Uracil, 1-benzyloxy-... 

In at least one case, the standard Bucherer-Bergs conditions gave rise to oxazole rather hydantoin. Specifically, when 5-benzyloxy-pyridine-2-carbaldehyde (11) was treated with potassium cyanide, ammonium chloride, and ammonium carbonate in boiling ethanol/water, 5-amino-oxazol-2-ol 12 was obtained. Subsequent heating of oxazole 12 with acetic acid at reflux overnight then produced the Bucherer-Bergs product, hydantoin 13. ... 

Amino-2-phenyl-2//-benzotriazole reacted with epichlorhydrin in chlorobenzene at 140-145°C to give the A-benzyl-7-hydroxy-6,7,8,9-tetrahydrotriazolo-quinoline derivative 194. This was benzylated and rearranged by heating in DMSO to give the isomeric 7-benzyloxy derivative 195 (Scheme 59) (77MI2). 

Preparation of a-Acety/amino-0-(5-Benzy/oxy-/ndo/yl-3)-Propionic Acid 15 grams a-acetyl-amino-0 -carboxy-/3-(5-benzyloxy-indolyl-3)-propionic acid was suspended in 225 ml water and the suspension refluxed and stirred in a stream of nitrogen until evolution of carbon dioxide ceased (about 2 hours). After cooling somewhat, 120 ml ethyl alcohol was added and the suspension refluxed until the product dissolved. Charcoal was added to the solution the mixture filtered hot, and the filter-cake washed with 50 ml hot 50% aqueous ethanol. 0 -Acetylamlno-/3-(5-benzyloxy-indolyl-3)-propionic acid, MP 164° to 166°C, which crystallized from the filtrate on cooling, was collected, washed with an ice-cold mixture of 15 ml ethanol and 45 ml water, and dried in vacuo over silica gel (yield 11.1 grams, 83%). 

Analog erhalt man 5-Benzyloxy-3-(2-amino-athyl)-indol als Oxalat3 (81 % d.Th. F 162°, Zers.) bzw. 5-Benzyloxy-3-(2-amino-athyl)-indazol-Bis-hydrochlorid4 (30% d. Th. F 265°). 

Alkoxy-3-phenyl- 581 3-Amino- 112 3-Anilino-2,3-diphcnyl- 581 3-Benzyloxy-3-phenyl- 581... 

Benzylmercapto-3-(2-dimethylamino-alkyl)- 129 5-Benzyloxy-3-(2-amino-athyl)- 111 5-Benzyloxy-3-cyanmethyl- 111 5-Benzyloxy-3-dibenzylaminooxalyl- 242... 

A similar series of reactions was performed by Paulsen and Hdlck141 for the preparation of the T-antigenic, unprotected, amino acid-disaccha-rides 200 and 201, starting from the 4,6-0-benzylidene-N-(benzyloxy-carbonyl) benzyl esters 198 and 199, respectively, by condensation with 110 in the presence of mercury dicyanide-mercury dichloride and molecular sieves 4A, and deprotection of the product. Sinay and co-workers148 also reported the synthesis of hexa-O-acetyl derivatives of 200 and 201 by application of the sequence of azido-nitration-bromination. 

L-alanylglycyl-L-cysteinyl-L-lysyl-L-asparaginyl-L-phenylalanyl-L-phenylalanyl-L-tryptophanyl-L-lysyl-L-threonyl-L-threonyl-L-cysteine 6-0-benzoyl-N-(benzyloxycarbonyl) methylamide 4,6-0-benzylidene-N-benzylidene-N-(benzyloxycarbonyl) methylamide N- (benzyloxy carbonyl) -N-(benzyloxycarbonyl)-, amide N-(benzyloxycarbonyl)-, hydrazide N-(benzyloxycarbonyl)-, methylamide N-(benzyloxycarbonyl)-, methyl ester N-(benzyloxycarbonyl)-L-alanyl-L-alanine methyl ester N-(benzyloxycarbonyl)-L-alanylglycine ethyl ester N-(benzyloxycarbonyl)glycyl-L-alanine methyl ester 3,4,6-tri-0-acetyl-2-amino-2-deoxy-N-(benzyloxycarbonyl)-, benzyl ester, hydrochloride... 

The deprotection of the Cbz protected amino acid proceeds via a two step mechanism (Figure 1). The first step comprises the catalytic hydrogenolysis of the benzyloxy group of the Cbz-protected amino acid (1). Toluene (3) is formed from the O-benzyl group as well as an unstable carbamic acid intermediate (2). This intermediate decomposes to form the unprotected amino acid (4) and carbon dioxide (5). 

For Schiff base being a derivative of gossypol and R-( I )-2-amino-3-benzyloxy-1-propanol, the conditions of the atropisomerisation were determined on the basis of the NMR spectra.37 The ratio of the diastereomers was established on the basis of the integrals of selected H signals (H-l and H-ll). The atropisomerisation of the gossypol Schiff base took place even if the samples were not exposed to the sunlight, however, this process was slower in the dark. The diastereopure Schiff bases were converted into a racemic mixture after ca. 12-14 h in the dark and ca. 3-3.5 h after irradiation of monochromatic light. The addition of a drop of water to acetonitrile solution accelerated the atropisomerisation. In this case, the 1 1 ratio of diastereomers was achieved after 45 min. The results obtained indicated that the atropisomerisation process cannot be considered as a simple photo-atropisomerisation. 

Mild acidic hydrolysis of amino nitrile 369 gave m-4,9a-/7-rra r-9-7/-9-benzyloxy-4-phenyl-3,4,9,9a-tetrahydro-17/,67/-pyrido[2,l-d[l,4]oxazin-l-one <1996TL4001>. (2A)-2-Cyano-l-[(lR)-2-hydroxy-l-phenylethyl]piperidin-6-one, on standing for 20 days in ethanol saturated with HC1 gas, afforded (4/ ,9aA)-4-phenylperhydropyrido[l,2-4[l,4]oxazine-l,6-dione, which was sometimes accompanied by the unstable (26 )-l-[(l/ )-2-hydroxy-l-phenylethyl]-... 

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