John H. P. Tyman

The UV–visible absorption and fluorescence of some substituted 1,8-naphthalimides and naphthalic anhydrides

A number of substituted 1,8-naphthalimides and naphthalic anhydrides have been prepared and their absorption and fluorescence properties in absolute ethanol have been determined. In the absence of an alkylamino substituent in the naphthalene ring, the compounds are colourless and weakly fluorescent. In the presence of such a substituent they become yellow and frequently fluoresce strongly with quantum yields of the order of 0.8.

The extraction of natural cashew nut-shell liquid from the cashew nut (Anacardium occidentale)

In the two-stage recovery of natural cashew nut-shell liquid (CNSL) by solvent extraction, the overall yields from half-shells obtained by mechanical cutting and from chilled fragmented shells (to solidify the phenols) by manual processing are identical, indicating that no physical loss of phenolic material occurs in the mechanical process. At the first stage, prior to comminution, the yield from intact half-shells of mechanical origin is considerably less than that from manually processed shells due to extensive internal fracturing of the shell structure and greater solvent penetration in the latter case. Static solvent extraction of macerated shells gave the same yield as Soxhlet extraction, but the filtration stage was difficult and large volumes of solvent were required. Soxhlet solvent extraction or ultrasound/solvent extraction of manually processed shells at ambient temperature gave similar yields and economy in solvent usage. Both were much superior to mechanical agitation. By catalyzed decarboxylation of the recovered natural CNSL an almost theoretical yield (25%) of phenolic lipid rich in cardanol was obtained, which is considerably higher than that (10%) in the traditional recovery of technical CNSL by the hot oil bath industrial method. Natural CNSL contains a predominant amount of anacardic acid and represents a novel phenolic lipid source. Chemical reduction with air/aqueous hydrazine gave saturated natural CNSL. Polymerization of natural CNSL was effected in alkaline solution with paraformaldehyde.

Nucleophilic displacement of the nitro group in 2- and 4-nitronaphthalic-1, 8-anhydrides and their derivatives

Abstract The nitro group in 2- and 4-nitronaphthalic-1,8-anhydrides can be substituted by amines in certain cases with retention of the anhydride grouping.

Practical liquid chromatographic separation of the phenols in technical cashew nutshell liquid fromAnacardium occidentale

The practical separation of cardanol from technical cashew nutshell liquid or its distillate has been effected by liquid chromatography on Silica Gel H 60 (TLC type) with solute/absorbent in the range 1∶5–1∶6. Concentrates of the monoene, diene and triene constituents of cardanol have been prepared by argentation liquid chromatography on Silica Gel H 60 with dry incorporation of 15% silver nitrate. The present use of pressurized columns was made prior to the advent of flash chromatography.

Enhancement of the Rate of Mannich Reactions in Aqueous Media

Abstract The rate of Mannich reaction of phenols and of ketones with secondary amines is greatly increased in aqueous compared with alcoholic or hydrocarbon solvents. Two phase systems are present and a phase transfer catalysis may be operative. With phenols and excess co-reactants the products are mono- or isomeric disubstituted dialkylaminomethyl derivatives dependent upon the reaction time.

Long chain phenols: Part XI. Composition of natural cashew nutshell liquid (Anacardium occidentale) from various sources.

The composition of cashew nutsAnacardium occidentale from different terrestrial sources has been studied. Samples from Brazil, Ceylon, Kenya, Mozambique, Nigeria, and Tanzania have been solvent extracted to recover the phenolic shell liquid (natural CNSL) separate from the kernel oil. The recovered materials from the different sources were present from 23.6% to 27.7%. After hydrogenation of the side chains and methylation of the acidic groups, the component phenols anacardic acid (74.1% to 77.4%), cardol (15.0% to 20.1%), 2-methyl cardol (1.7% to 2.6%), and cardanol (1.2% to 9.2%) were determined by gas liquid chromatography on polyethyleneglycol adipate. The component phenols have been separated by adsorption thin layer chromatography, and their triene (AN-15∶3, 36.3% to 50.4%), diene (AN-15∶2, 17.8% to 32.1%), monoene (AN-15∶1, 25.0%, to 33.3%), and saturated (AN-15∶0, 2.2% to 3.0%) constituents determined by mass spectroscopy. The results of mass spectroscopic analysis have been confirmed by methylation of the separated component phenols and gas liquid chromatography. It is apparent that the largest variation is in the % cardanol (1.2% to 9.2%). While the total percentage of unsaturated constituents is quite similar, the distribution of triene, diene, and monoene varies widely.

The synthesis of 2-hydroxymethyl derivatives of phenols

2-Hydroxymethylphenols have been prepared in good yield by reduction with sodium borohydride of the precursor aldehydes, obtained regiospecifically from reaction of phenols with paraformaldehyde in toluene containing stannic chloride and tri-n-butylamine. By contrast, reaction of phenols with either paraformaldehyde under anhydrous conditions or with aqueous formaldehyde results in formation of both the hydroxymethyl and the bishydroxymethyl derivatives. Cyclic acetals of the precursor aldehydes are readily accessible.

Synthesis of carminic acid, the colourant principle of cochineal

The first synthesis of carminic acid (7β-D-glucopyranosyl-3,5,6,8-tetrahydroxy-1-methyl-9,10-dioxo-9,10-dihydroanthracene-2-carboxylic acid) is described. Selective C-glycosylation at the 7-position of ethyl and benzyl 3,5,8,9,10-pentamethoxy-1-methylanthracene-2-carboxylates with 2,3,4,6-tetra-O-benzyl-1-trifluoroacetyl-α-D-glucopyranose afforded intermediates which were oxidised to ethyl and benzyl 3,5,8-trimethoxy-1-methyl-9,10-dioxo-7-(2′,3′,4′,6′-tetra-O-benzyl-β-D-glucopyranosyl)-9,10-dihydroanthracene-2-carboxylate respectively. The benzyl compound was hydrogenolysed and the ethyl analogue hydrogenolysed and hydrolysed to give the same product, which was tetraacetylated and demethylated to afford 6-deoxycarminic acid tetraacetate, 3,5,8-trihydroxy-1-methyl-9,10-dioxo-7-(2′,3′,4′,6′-tetra-O-acetyl-β-D-glucopyranosyl)-9,10-dihydroanthracene-2-carboxylic acid. The pentamethoxy intermediates were obtained from 2-chloronaphthazarin by Diels–Alder addition to 3-alkoxycarbonyl-2,4-bis(trimethylsiloxy)penta-2,4-dienes to give alkyl 6-deoxykermesates. Methylation afforded the corresponding trimethyl ethers, which by reductive methylation gave the required pentamethoxy compounds. By known steps 6-deoxycarminic acid tetraacetate was converted into the 5,8,9,10-bisquinone, acetoxylation of which gave carminic acid octaacetate. Acidic hydrolysis afforded carminic acid.

Long chain phenols. Part 17. The synthesis of 5-[(Z)-pentadec-8-enyl]resorcinol, ‘cardol monoene,’ and of 5-[(ZZ)-pentadec-8,11-dienyl]-resorcinol dimethyl ether, ‘cardol diene’ dimethyl ether

Two unsaturated compounds in the ‘cardol’ series, an important component phenol from Anacardium occidentale, have been synthesised. 3,5-Dimethoxybenzaldehyde interacted with OH-protected 6-chlorohexan-1-ol in the presence of lithium to give, after acidic treatment, 1-(3,5-dimethoxyphenyl)heptane-1,7-diol which was hydrogenolysed selectively to 7-(3,5-dimethoxyphenyl)heptan-1-ol. Conversion into the bromide and alkylation of lithio-oct-1-yne gave 5-(pentadec-8-ynyl)resorcinol dimethyl ether which was selectively converted into the 8-(Z)-alkene. Demethylation with lithium iodide gave 5-[(Z)-pentadec-8-enyl]resorcinol which was identical to ‘cardol monoene’. Reaction of 7-(3,5-dimethoxyphenyl)heptyl bromide with the lithium derivative of OH-protected propargyl alcohol, gave after acidic treatment 10-(3,5-dimethoxyphenyl)dec-2-yn-1-ol, the bromide of which with pent-1-ynylmagnesium bromide afforded 5-pentadec-8,11-diynylresorcinol dimethyl ether. Selective hydrogenation yielded 5-[(ZZ)-pentadeca-8,11-dienyl]resorcinol dimethyl ether identical with the dimethyl ether of ‘cardol diene.’

The synthesis of symmetrical and unsymmetrical alkylaminonaphthalic-1,8-N-alkylimides

Symmetrical 4-n-alkylamino and 2-(n-alkylamino)naphthalic-1,8-N-alkylimides are prepared with primary amines from 4- and 2-halogenonaphthalic-1,8-anhydrides in N-methylpyrrolidinone. 3-Halogenonaphthalic-1,8-anhydrides only react at the anhydride. Unsymmetrical 4-compounds result by reaction of primary amines with the anhydride in ethanol and then the 4-halogeno-N-alkyl product in N-methylpyrrolidinone with primary or secondary amines © 2000 Society of Chemical Industry