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A new single-step efficient photocchemical approach for α-arylpropanoic acids ( 4 ) from α chloro-propiophenones ( 5 ) is described. It involves carbonyl triplet excited state directed 1,2-aryl migration of the aryl group which has been found to be highly dependent upon the nature of the aryl substituent. The mode of this rearrangement is probed by the study of the photobehaviour of a set of optically active α-chloro-propiophenones. The results suggest that the nature of the carbonyl triplets (n,π * /π,π * ) plays an important role in the chirality transfer. This method finds application in the synthesis of optically active ibuprofen ( 4e ) and ketoprofen ( 26 ), though in moderate optical yields.

A regiospecific synthesis of bikaverin (1) is described starting from methyl 2-hydroxy-4-methoxy-6-methyl benzoate (2) and 2-chloro-5,7-dimethoxy-1,4-naphoquinone (4).

The reaction of acetanilide (1) with nitrobenzene (2) in the presence of a base in DMSO yielded p -nitrosodiphenylamine (3) as the major product. This unusual regioselective formation of the deoxygenated product 3 has been rationalized in terms of solvent effects exerted by DMSO.

Photolysis of the enones 4a–c leads to regioselective hydrogen abstraction and subsequent cyclization to furnish the spiro compounds 5a–d, which on further elaboration provide the spiro dione 6, a model for the antitumour antibiotic, fredericamycin-A 1.

Synthesis of (±)heritol and epi -heritol is described. The key step is the osmylation of the unsaturated ester 9a. Osmylation is used as a tool to construct the α,β-unsaturated γ-lactone system.

Osmylation of β,γ-unsaturated esters and acid catalysed cyclisation of the resultant diols generate butenolides in high yields.

Osmylation of β,γ-unsaturated esters and acid catalysed cyclisation of the resultant diols generate butenolides in high yields.

Substituted aromatic amides were alkylated under PTC conditions. Compounds with ortho electron withdrawing substituents furnished exclusively monoalkyl amines. A plausible mechanism has been suggested.

Synthesis of (±)heritol and epi -heritol is described. The key step is the osmylation of the unsaturated ester 9a. Osmylation is used as a tool to construct the α,β-unsaturated γ-lactone system.

We report in this paper an high resolution (R s =2,5) HPLC method using a silica gel column and 50% watersaturated diethyl ether-n-hexane (25:75) as the mobile phase with detection at 280 nm for the determination of underivatized 2-naphthylamine in technical 1-napthtylamine with sub-ppm as the lower detection limit in n-hexane solution

A fast, efficient and reproducible method for the separation of the five major opium alkaloids by thin-layer chromatography coupled to flame ionization detection is reported. The alkaloids were separated without derivatization on silica rods of type SII using the partial scanning or peak pyrolysis method —where organic matter separated on the rods are burnt when they pass through the hydrogen flame— between the stages of a two-step development system. The first development, in benzene-acetonitrile-ethyl acetate (60:20:20, v/v) separated narcotine and papaverine. Morphine, codeine and thebaine were separated during the second development in ethyl acetate-benzene-acetonitrile-ammonium hydroxide (25:30:40:5, v/v). The best binary solvent system was benzene-ethanol (9.5:0.5, v/v) and (9:1, v/v) which separated all the five alkaloids simultaneously.

Several newer disperse dyes 3a-3l have been synthesized from phenyl 3-aminobenzenesulphonates as diazo-components. Their coloristic and dyeing properties have been evaluated, and their performance compared with corresponding dyes 5 derived from 3 -aminophenyl phenylsulphonates 4 . The new dyes 3 possess good fastness and dyeing properties. Moreover, they have higher tinctorial strength as compared with the dyes 5 , which include the commercial dye Samaron Yellow 6 GRL ( 5b ), making them highly competitive commercially.

Several new 3-substituted benzoxazolyl/benzimidazolyl-7-diethylamino-2H-1-benzopyran-2-one laser dyes have been synthesized and their lasing characteristics evaluated. The spectral properties and dyeing characteristics of the new dyes are also discussed. The dyes 3b 3d and 3g showed great promise as efficient laser dyes with strong possibilities of commercial exploitation. Moreover, the new dyes imparted brilliant greenish yellow shades on polyester with moderate to good fastness properties making them suitable for use as disperse dyes.

The chemical constitution of C.I. Disperse Yellow 232 [Intrasil Brilliant Yellow 10GF] was elucidated as 3-(5'-chloro-2'-benzoxazolyl)-7-diethyl-ammo-2H-1-benzopyran-2-one ( 1 ). The structure of the dye was confirmed by synthesis from commercially available starting materials. The relative merits of different methods for the preparation of 1 are also discussed.

The reaction of α-chloroacyl chlorides with glycine Schiff bases affords 3-oxazolines.

The reaction of acetanilide (1) with nitrobenzene (2) in the presence of a base in DMSO yielded p -nitrosodiphenylamine (3) as the major product. This unusual regioselective formation of the deoxygenated product 3 has been rationalized in terms of solvent effects exerted by DMSO.

Irradiation of the title compound and related caged cyclobutyl diones in alcoholic solvents at 300 nm furnishes good yields of monoacetals and leads to products arising from β-cleavage and dual epimerization.

The behaviour of some enamine-esters, -ketones and -nitriles under electron impact has been investigated by means of low-resolution mass Spectrometry.

The behaviour of some benzoylnitroanilines and their derivatives under electron impact ionization was investigated by means of low-resolution mass spectrometry. Some characteristic rearrangement processes are discussed

(1990). AN ALTERNATIVE METHOD FOR TOLNAFTATE. Organic Preparations and Procedures International: Vol. 22, No. 1, pp. 128-130.

A novel synthesis of unsymmetrical azo aromatics inaccessible by diazo-coupling reaction is reported. The synthesis involved the reaction of acetanilides with nitroarenes under moderate reaction conditions. A reaction pathway via a nitrosoarene intermediate involving elimination of the elements of the acetate anion, is proposed.

An efficient, one pot strategy for the synthesis of spiro [4. n]dione and 2,2-disubstituted cyclopentane-1,3-dione has been developed by using ketals and 1,2-disilyloxycyclobutene in the presence of excess BF 3.Et2O.

Stereoselective synthesis of (±)-diacetylobafluorin and (+)-SQ 26,517 has been accomplished via transacylation of α-N-(2-nitrophenyl)sulphenyl-β-lactones with 2-acylmercaptobenzothiazoles.

The first total synthesis of Monocillin IV dimethyl ether (1a) was achieved from methyl-9-acetoxy-6-decenoate (6) and orsellinic acid dimethyl ether (7) in two steps.

A strategy based on photochemical 1,2-aryl migration as the pivotal step allows efficient transformation of 2-chloro-propiophenones into 2-arylpropionic acids. A noticeable substituent-directed excited state control on the rearrangement process has been observed.

Photolysis of the enones 4a–c leads to regioselective hydrogen abstraction and subsequent cyclization to furnish the spiro compounds 5a–d, which on further elaboration provide the spiro dione 6, a model for the antitumour antibiotic, fredericamycin-A 1.

A short, convergent synthesis of (±) patulolide A, a 12-membered macrolide with high antifungal activities is hereby reported. It has been achieved in 10 steps from 1-bromopentanal and 4-hydroxypent-1-yne.

Treatment of azaallyl anions, generated from glycine Schiff bases, with Ar-acyl halides furnishes N-acylaziridines via intramolecular cyclization.

A number of diacetanilides, including some which have not been reported so far, have been synthesized from the corresponding monoacetyl derivatives and characterized by spectral and elemental analyses. A tlc/fid method for the quantitative estimation of the relative amounts of mono- and diacetyl derivatives has been standardized. Linear correlation of the extent of diacetylation with Hammett σ-values of substituents and basicity constants of monoacetyl derivatives has been established. A plausible mechanism for the diacetylation reaction based on experimental observations has been suggested. An explanation for the anomalous behaviour of acetanilides containing electron-withdrawing substituents in the ortho position has been put forth.

Five 4-(2′-phenylisopropyl)phenol esters were synthesized and their properties as stationary phases in gas—liquid chromatography were investigated. Their McReynolds' constants were determined. To investigate their selectivity, different aromatic positional isomers were used as solutes. Quantitative analyses were carried out for some of these isomers. These new esters may offer some advantages for gas chromatography.