160875-42-3

Upstream product

• 118-93-4 o-hydroxyacetophenone 
• 79-04-9 chloroacetyl chloride 

Downstream Products

• 607-71-6 4-methyl-2H-chromen-2-one 
• 3782-00-1 2,3-dimethylbenzofuran 

Relevant academic research and scientific papers

Reduction of substituted phenyl 2-chloroacetates at silver cathodes: Electrosynthesis of coumarins

To explore the electrosynthesis of coumarins, cyclic voltammetry and controlled-potential (bulk) electrolysis have been employed to investigate the reduction of the carbon-chlorine bond of five substituted phenyl 2-chloroacetates at silver cathodes in dimethylformamide (DMF) containing 0.10 M tetra-n-butylammonium tetrafluoroborate (TBABF4) as supporting electrolyte; the five substrates are 2-formylphenyl 2-chloroacetate (1a), 2-acetylphenyl 2-chloroacetate (2a), methyl 2-(2-chloroacetoxy)benzoate (3a), 2-formyl-5-methoxyphenyl 2-chloroacetate (4a), and 2-formyl-3,5-dimethoxyphenyl 2-chloroacetate (5a). We have examined (a) the effects of substituents on the benzene ring of the substrate as well as the nature of the aryl carbonyl moiety on the formation of the coumarin product and (b) the effect of solvent - namely, DMF, acetonitrile (CH3CN), benzonitrile (PhCN), and propylene carbonate (PC) - and substrate concentration on the yield of the coumarin. It was found that the most unsubstituted substrate (1a) afforded the highest yield (41%) of the desired coumarin in a DMF-TBABF4 medium. A mechanistic scheme is proposed to account for the formation of the coumarin. Furthermore, the only other products seen in these reductions are 2-substituted phenols, which are precursors for synthesis of the various substrates.

Short communication: Titanium-induced synthesis of benzofurans

Ketoesters derived from the acylation of o-hydroxyacetophenone with aliphatic as well as aromatic acid chlorides undergo intramolecular cyclization in the presence of low-valent titanium to afford benzofurans in good yields. The reduction of titanium trichloride with dry zinc powder in refluxing THF takes place in the presence of the ketoester which simultaneously cyclizes as the titanium catalyst is formed, rendering the pre-reduction of titanium trichloride in a separate step unnecessary.

Synthesis of Hetaryl Pyridinium Salts and Fused 3-Amino-pyrid-2-ones

1-(3-Coumaryl)-pyridinium salts 3 and 1-(3-coumaryl)-tetrahydrothiophenium salts 5 were synthesized from 2-acylphenyl chloro- or bromoacetates 2. 2-Chloro-N1-(3,4-dimethoxyphenyl)-acetamide and substituted 2-chloro-N1-(2-thienyl)-acetamides 8 react with acetyl chloride and pyridine to yield the quinolinyl- and (thieno[2,3-b]pyridin-5-yl)-pyridinium salts 10. Fused thieno[2,3-b]pyridin-ones 19 were formed from N-chloroacetyl-2-aminothiophen-3-carbonitriles 16 with pyridine via Thorpe-Ziegler cyclization and followed by cyclodehydrogenation. In presence of pyridine alkyl 2-chloro-acetylaminobenzoates 21 yield 3-(1-pyridinio)-quinoline-4-olates 23. Zincke-cleavage of 10 and 23 with hydrazinium hydroxide leads to fused 3-amino-pyridine-2-ones 11 and 3-amino-4-hydroxy-quinoline-2-ones 24, respectively. Oxazoloquinolines 25 were synthesized from 24 with acetic anhydride.