Mohamed M. Abdel Rahman

Transformation of the hydrazones of 6-chloro-3-(l-threo-2,3,4-trihydroxy-1-oxobutyl)-2-quinoxalinone into other heterocyclic compounds

Abstract The difference in reactivity of the two amino groups in 4-chloro- o -phenylene-diamine allowed it to react with l - threo -2,3-hexodiulosono-1,4-lactone to give, after further reaction with various hydrazines, 6-chloro-3-(1-substituted-hydrazono- l - threo -2,3,4-trihydroxybutyl)-2-quinoxalinones ( 5-14 ), whose structures were deduced from their reactions, as well as from mass spectrometry of the ( p -nitrophenyl)-hydrazone. Elimination of one mole of water per mole from these hydrazones gave the 1-aryl-6-chloro-3-( l - threo -glycerol-1-yl)flavazoles; the mass spectrum of one of these flavazoles is discussed. Elimination of two moles of water per mole from the hydrazones ( 5, 7, and 8 ) occurred with simultaneous cyclization to give 3-[l-aryl-5- (hydroxymethyl)pyrazol-3-yl]-6-chloro-2-quinoxalinones. whose acetylation gave the corresponding- monoacetyl derivatives (that could also be obtained by the action of boiling acetic anhydride on the starting hydrazones). Periodate oxidation of the hydrazones and the flavazole derivatives afforded the corresponding aldehydes (that could react with hydrazines).

C-(polyacetoxy)alkyloxadiazolines and related compounds

Abstract The (phenylacetyl)hydrazones of d -galactose, d -glucose, d -mannose, d -arabinose, l -arabinose, d -xylose, and l -sorbose were prepared. The d -galactose and d -arabinose derivatives were converted into their per- O -acetylated derivatives ( 8 and 9 , respectively). The acyclic structure of 8 was proved from its direct preparation by the condensation of(phenylacetyl)hydrazine with penta- O -acetyl-aldehydo- d -galactose. Cyclization of 2,3,4,5,6-penta- O -acetyl- aldehydo - d -galactose (phenylacetyl)hydrazone with boiling acetic anhydride yielded a mixture of two products that could be separated by fractional recrystallization, to give 3-acetyl-5-benzyl-2-(polyacetoxy)alkyl-1,3,4-oxadiazolines; a mechanism for the reaction was proposed. The n.m.r. and mass spectra of some of these derivatives were discussed.

Reaction of dehydro-d-erythorbic acid and its aryl analogs with ortho-diamines

Abstract Condensation of 3-( d - erythro -2,3,4-trihydroxy-l-oxobutyl)-2-quinoxalinone and its 6-chloro derivative (obtained by the reaction of d - erythro -2,3-hexodiulosono-1,4-lactone with ortho -diamines) with aryl- or aroyl-hydrazines gave 3-[l-(phenylhydrazono)- d - erythro -2,3,4-trihydroxybutyl]-2-quinoxalinone (5) and relatives. Whereas boiling acetic anhydride causes the loss of two molecules of water per molecule of such hydrazones, affording, the 3-[5-(acetoxymethyl)-l-arylpyrazol-3-yl]-2-quinoxalinones, identical with those obtained from the l - threo isomer, alkali causes the loss of only one molecule, affording, the corresponding flavazoles. Periodate oxidation of 5 gave 3-[l-(phenylhydrazono)glyoxal-l-yl]-2-quinoxalinone, which afforded the corresponding mixed bis(hydrazones). A similar sequence of reactions was conducted with the aryl analogs, 4-phenyl-2,3-dioxobutano-1,4-lactone and its p -chlorophenyl derivative, whereby the 3-[2-aryl-l-(arylhydrazono)-2-hydroxyethyl]2-quinoxalinones, were prepared; these were transformed into 3-(α-hydroxybenzyl)-flavazoles that gave monoacetyl derivatives.

Synthesis of nitrogen-heterocyclic analogs of L-ascorbic acid: a triazolyl analog and its reactions☆

Abstract A triazolyl analog of dehydro- L -ascorbic acid (also a C -nucleoside analog) was prepared. The reaction of 4-formyl-2-phenyl-1,2,3-triazole with glyoxal in the presence of potassium cyanide, through an acyloin condensation followed by a cyanohydrin reaction, gave 2,5-dihydro-3,4-dihydroxy-5-imino-2-(2-phenyl-1,2,3-triazol-4-yl)-5(2 H )-furanone ( 6 ) that gave a monoacetyl derivative. Reaction of 6 with nitrous acid afforded 2,3-dioxo-4-(2-phenyl-1,2,3-triazol-4-yl)butano-1,4-lactone ( 10 ) that, upon reaction with phenyl- or ( p -nitrophenyl)-hydrazine, gave the 4-(2-phenyl-1,2,3-triazol-4-yl)butano-1,4-lactone 2,3-bis(arylhydrazones) ( 12 or 13 ). Rearrangement of 12 gave hydroxy-[1-phenyl-4-(phenylhydrazono)-2-pyrazolin-5-one-3-yl]-(2-phenyl-1,2,3-triazol-4-yl)methane ( 16 ), which gave a monoacetyl derivative. Treatment of 6 with phenylhydrazine in aqueous acetic acid gave [l-phenyl-4-(phenylhydrazono)-2-pyrazolin-5-one-3-yl]-(2-phenyl- 1,2,3-triazol-4-yl)methane, which is the deoxygenated analog of 16 . Reaction of 10 with o -phenylenediamine and phenylhydrazine afforded a red product identified as 1-hydroxy-2-(phenylhydrazono)-1-(2-phenyl-1,2,3-triazol-4-yl)-2-(2-quinoxalinone-3-yl)ethane ( 19 ) which, upon treatment with alkali, gave hydroxy-(1-phenylflavazol-3-yl)-(2-phenyl-1,2,3-triazol-4-yl)-methane ( 20 ). Acetylation of 20 gave the acetoxy-(1-phenylflavazol-3-yl)-(2-phenyl-1,2,3-triazol-4-yl)methane ( 21 ). This sequence, 10→19→21 , confirms the initial position of the reaction of o -phenylenediamine with 10 . The structures of the products were deduced from their mode of preparation, chemical reactions, and spectral data.

Symthesis of 3-[1-(p-Fluorophemyl)-Pyrazol-3-YL]-Quimoxalimomes

Abstract 3-[1-(p-Fluorophenylhydrazono)-L-threo-2,3,4-tri hydroxybutyl1-2-quinoxalinowe was prepared and trarrsformed to 3-[5-acetoxymetnyl-1-(p-fluorophenyl)-pyrazol-3-yl]-2-quinoxalinone. N-methylation, followed oy dehydrative cyclisation, gave the M-methyl-derivative of the latter pyrazole. Periodate oxidation gave a glyoxalyl derivative whose aldehyde functionality was confirmed by reduction and oximation.

Synthesis of 3-deoxy-4-O-β-D-galactopyranosyl-D-erythro-hexos-2-ulose and of some of its derivatives from lactose

Abstract 3-Deoxy-4-O-β- D -galactopyranosyl- D -erythro-hexos-2-ulose (1) was obtained from lactose by reaction with benzoylhydrazine in the presence of a slightly acidic solution of p-toluidine, followed by hydrazinolysis of the product, 3-deoxy-4-O-β- D -galactopyranosyl- D -erythro-hexos-2-ulose bis(benzoylhydrazone) (3), with benzaldehyde. A variety of derivatives of 1 and 3 was prepared. Lactose aroylhydrazones were also prepared. Quantitative determination of the oxidant during the periodate oxidation of 3 was studied. Periodate oxidation of monosaccharide arylhydrazones gave glyoxal mono(arylhydrazones) which afforded the corresponding, mixed bis(hydrazones).

The Pyranoid C6-Portion of the Natural C12--α,β-Unsaturated-δ-Lactones From D-Glucose

Abstract The transformation of D-glucose to 5,6-disubstituted 5,6-dihydro-2H-pyran-2-one 3, an analogue of the (5R)-C6-pyranoid part of the natural α,β-unsaturated-δ-lactones is described.