Acetyl salicylaldehyde

Basic catalysts other than alkali acetates have been employed in the Perkin reaction thus salicylaldehyde condenses with acetic anhydride in the presence of triethylamine to yield coumarin (tlie lactone of the cis form of o-hydroxy-cinnamio acid) together with some of the acetyl derivative of the trans form (o-acetoxycoumaric acid) ... 

Comforth has reviewed literature reports and independently studied the special cases of reaction of 1 with salicylaldehyde and with 2-acetoxybenzaldehyde. Coumarins (10) are afforded in the condensation of 1 with salicylaldehyde or its imine, whereas when 2-acetoxybenzaldehyde is used, acetoxy oxazolone 12 is the major product. The initial aldol condensation product between the oxazolone and 2-acetoxybenzaldehyde is the 4-(a-hydroxybenzyl)oxazolone 11, in which base-catalyzed intramolecular transacetylation is envisioned. The product 9 (R = Ac) can either be acetylated on the phenolic hydroxy group, before or after loss of acetic acid, to yield the oxazolone 12, or it can rearrange, by a second intramolecular process catalyzed by base and acid, to the hydrocoumarin, which loses acetic acid to yield 10. When salicylaldehyde is the starting material, aldol intermediate 9 (R = H) can rearrange directly to a hydrocoumarin. Comforth also accessed pure 4-(2 -hydroxyphenylmethylene)-2-phenyloxazol-5(4//)-one (13) through hydrolysis of 12 with 88% sulfuric acid. 

Coordination compounds containing bidentate ligands are often thermally more stable than those comprised of related monodentate ligands, e.g. ethylenediamine (en) complexes dissociate at a higher temperature than those of ammonia or pyridine. Compounds containing a ring structure, such as coordinated salicylaldehyde (sal) and acetyl-acetonate (acac), are particularly stable, and may often be sublimed... 

Salicylic acid is manufactured on a large scale. In the dye industry it serves for the production of valuable azo-dyes which exhibit great fastness. To some extent these dyes are applied to mordanted fibres. In addition, the acid and its derivatives are widely used in pharmacy. Being a phenolcarboxylic acid it has a powerful disinfecting action (preservative). It has further proved itself an important antirheumatic and an analgetic. The derivative in which the phenolic hydroxyl group is acetylated (aspirin) has become especially popular. The first medicament of the series was the phenyl ester of salicylic acid, salol, which is produced as a by-product in the technical process. The preparation of salicylaldehyde has been described above (p. 235). 

NMR spectra were measured. As RuCl(H20)(csb)2/02/Me2CHCH0/CH2Cl2/4°C it asymmetrically epoxidised styrene and substituted styrenes with e.e. of up to 30% [798]. Complexes with (csb =lR,2R(-)l,2-diaminocyclohexane with 3-acetyl-4-hydroxy-6-methyl-2-pyrone and salicylaldehyde, 5-chloro-5-methoxy, 5-methoxy and 5-nitrosalicyladehyde) asymmetrically epoxidised styrene as RuCKH O) (csb )2/PhIO/CH3CN [799]. 

Aldehyde formation Reimer-Tiemann reaction Treatment of a phenol with chloroform (CHCI3) and aqueous hydroxide introduces an aldehyde group (—CHO) onto the aromatic ring, generally ortho to the —OH group. A substituted henzalchloride is initially formed, but is hydrolysed by the alkaline medium. Salicylaldehyde can be produced from phenol by this reaction. Again, salicylaldehyde could be oxidized to sahcylic acid, which could be acetylated to aspirin. 

The reaction of Zr(OCHMe2)4-HOCHMe2 with dibasic ONNO-tetradentate Schiff base ligands derived from diaminoalkanes and salicylaldehyde, 2-hydroxy-l-naphthaldehyde, acetyl-... 

Reaction XCI. (b) Oxidation of Aromatic Hydrocarbons to Aldehydes by the action of Chromic Acid in Acetic Anhydride Solution. (A., 311, 353 D.R.P., 121788.)—In the ordinary way, chromic acid oxidises hydrocarbons to aldehydes and then to acids. But if acetic anhydride and cone, sulphuric acid is present, the di-acetyl derivative of the aldehyde is formed and this does not undergo further oxidation. The aldehyde is obtained from the di-ester by hydrolysis. (Cf. the preparation of salicylaldehyde, p. 105.)... 

Et2AlCl could be replaced by the sesquichloride or by a mixture of a trialkylaluminum and a reactive halide such as benzyl chloride or tert-butyl chloride. The effective cobalt compounds were those which are known to yield cis-1,4-polybutadiene—e.g. cobalt stearate, cobalt acetyl-acetonate, cobalt bis(salicylaldehyde imine), cobalt chloride-pyridine, etc. Et2AlCl concentration could be varied within the range 0.3-5% by weight based on PVC, and the cobalt compound concentration was 0.002-0.01 mole per mole of Et2AlCl. 

Coumarin is formed from acetic anhydride and salicylaldehyde in the presence of triethylamine as the base catalyst. It is the lactone of the (Z)-form of o-hydroxycinnamic acid some of the ( )-isomer in the form of its acetyl derivative (o-acetoxycinnamic acid) is also obtained (Expt 6.138). 

Methyl Alcohol Methyl Alcohol Ethyl Alcohol Ethyl Alcohol Glycol Glycol Acetonitril Acetonitril Propionitril Propionitril Benzonitril Methyl Sulphocyanide Ethyl Sulphocyanide Nitro Methane Nitro Methane Nitroso Dimethylin Acetyl Acetone Furfurol Furfurol Benzaldehyde Salicylaldehyde... 

DMAP acts as an efficient acyl transfer agent, so that alcohols resistant to acetylation hy Acetic Anhydride-Pyridine usually react well in the presence of DMAP. Sterically hindered phenols can be converted into salicylaldehydes via a benzofurandione prepared by DMAP catalysis (eq 2). ... 

Ng bubbled overnight through acrolein and then through a fritted disk into a mixture of salicylaldehyde and aq. NaOH 2H-l-benzopyran-3-carboxaldehyde. Y 85%. - Similarly with methyl vinyl ketone 3-acetyl-2H-l-benzopyran. Y 72%. F. e. s. CD. deBoer, J. Org. Chem. 59, 2426 (1974). 

Sabinol, 75 Saccharic acid, 33 Salicylaldehyde, 52 Salicylamide, 49 Salicylic acid, 40, 48, 51, 52 acetyl-, 13 Salicyluric acid, 49 Saligenin, 15 Santenone, 79 Scurvy, 18 Sodium alginate, 20 Sodium benzoate, 31 Sodium n-butyrate, 29 Sodium feri-butyl acetate, 29 Stilbestrol, 81, 84 Streptomycin, 70 Synovial fluid, 15, 16 Syringaldehyde, 53 Sulfadiazine, 14, 62 Sulfamerazine, 62 Sulfamezathine, 62 Sulfanilamide, 61, 63 Sulfapyridine, 61, 62 Sulfathiazole, 61... 

Wang, Liu, and coworkers developed a CuBr2-catalyzed synthesis of coumarins using a wide range of a-EWG-substituted ketene S,S-acetals, including a-aroyl, acetyl, cyano, ethoxycarbonyl groups with salicylaldehydes under very mild conditions [192] (Scheme 8.117). 

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