Sanjay R. Chemburkar

Synthesis of Arylglyoxylic Acids and Their Collision-Induced Dissociation

Abstract A variety of substituted arylglyoxylic acids (2a−g) were synthesized via oxidation of the corresponding aryl-methylketones (1a–e) using selenium dioxide or Friedel–Crafts acylation of phenol (3) with ethyl chlorooxoacetate and further transformations. It was found that the arylglyoxylic acids (2) undergo facile unimolecular dissociation with loss of carbon monoxide to give the corresponding arylcarboxylic acids (7) under collisionally induced mass spectrometric conditions.

SYNTHESIS OF A-79175 : A SECOND GENERATION 5-LIPOXYGENASE INHIBITOR

Abstract A convergent, high yielding, and scalable synthesis of A-79175, with a key step involving a mild and efficient Cuue5f8Pd catalyzed coupling reaction of a terminal acetylene with a substituted 2-iodofuran is discussed.

Efficient Method for Synthesis of 2-Acetylbenzo(b)thiophene and Its Derivatives, the Key Synthons for 5-Lipoxygenase Inhibitors

An efficient method was developed for synthesis of 2-acetylbenzo(b)thiophene (2a), the key intermediate for zileuton (1). Synthesis involves treatment of 2-chlorobenzaldehyde (5a) with tert-butylmercaptan (6) to form 2-(tert-butylthio)benzaldehyde (7a), which upon treatment with HBr in water gave the disulfide derivative 2,2′-disulfanediyldibenzaldehyde (8a) in 97% yield. Finally, the reaction of 8a with acetylacetone (9) and 1-chloroacetone (10) gave 2-acetylbenzo(b)thiophene (2a) in 94% yield. The methodology is general and suitable for the preparation of its derivatives, 2b–d.