4281-21-4

Upstream product

• 643-79-8 o-phthalic dicarboxaldehyde 
• 89-51-0 Homophthalic acid 
• 119-67-5 o-carboxybenzaldehyde 
• 73049-16-8 stilbene-2,2'-dicarboxylic acid 
• 2975-71-5 2-[(3-oxo-1,3-dihydro-2-benzofuran-1-yl)methyl]benzoic acid 
• 56526-10-4 o,o'-Bis(methoxycarbonyl)stilbene 
• 7732-18-5 water 
• 91413-16-0 potassium 2-carboethoxybenzoate 
• 85-44-9 phthalic anhydride 
• 87-41-2 2-benzofuran-1(3H)-one 
• 4281-16-7 2-[2-(2-carboxyphenyl)acetyl]benzoic acid 
• 4281-19-0 α-(o-carboxybenzoyl)phtalide 
• 16859-59-9 3-hydroxy-1(3H)-isobenzofuranone 
• 140-29-4 phenylacetonitrile 

Downstream Products

• 1064110-31-1 1-(o-tolyl)-3-[1-(o-tolyl)benzo[c]thiophen-3-yl]benzo[c]thiophene 
• 72872-62-9 o,o'-benzil dicarboxylic acid 
• 2975-71-5 2-[(3-oxo-1,3-dihydro-2-benzofuran-1-yl)methyl]benzoic acid 

Relevant academic research and scientific papers

Photochemistry of o-Phthalaldehyde

U.v.-irradiation of o-phthalaldehyde leads to the formation of phthalide and dimeric products in varying yields and ratios depending on the solvent and reagent concentration.Laser flash photolysis studies show that the photochemistry of o-phthalaldehyde involves the intermediacy of a 1,4-biradical produced by intramolecular hydrogen transfer, and with a lifetime of 1.6 μs.Two triplet states are the precursors of the biradical; they have lifetimes of 6 and 36 ns and are assigned to different rotational conformers.The triplet reaction path is not responsible for product formation; these arise via a parallel reaction path, apparently involving the singlet state.

5-endo closure of the 2-formylbenzoyl radical

The 5-endo cyclization of the 2-formylbenzoyl radical (reaction 2) is shown to be a highly favored process relative to the alternative, 4-exo-trig ring closure. This evidence comes from product studies, including ESR and laser flash photolysis studies of transient radical intermediates, from a nitroxide trapping measurement of the rate constant for cyclization of the 2-formylbenzoyl radical, viz., k2 = 2 × 108 s-1 at 45 °C, and from the estimated favorable enthalpic change for 5-endo cyclization vs 4-exo-trig cyclization. It is suggested that rotation of the formyl group in the initially formed conformer of the 2-formylbenzoyl radical may be the rate limiting step in this cyclization.

New Olefin and Oxiran Syntheses from Carbonyl Compounds, and Diethyl Sodiophosphonate Anions and 1-Aminophosphonate Amino-anions

Reaction of aromatic aldehydes, and phthalic and thiophthalic anhydrides, with diethyl sodiophosphonate (1) gives the trans-stilbenes (3), 3,3'-biphthalidylidene (30), and 3,3'-bis-(2-thiophthalidylidene) (33).Similar treatment of fluorenone (8) and xanthone (17) with (1) leads to 9,9'-bis(fluororenylidene) (9) and 9,10-dihydro-9-oxophenanthrene-10-spiro-9'-fluorene (10), and to 9,9'-bixanthenylidene (18) and 9,9'-bixanthenyl (19), respectively, but the reaction using anthrone (11) as a carbonyl reagent yields only anthraquinone (12) and anthracene (13).Similar treatment using N-methylisatoic anhydride (34) and N-methylisatin (36) produces NN'-dimethylisoindigo (35).Reaction of benzaldehyde and p-chlorobenzaldehyde with diethyl 1--cyclohexylphosphonate (40) gives mainly corresponding mixtures of trans- (41a,b) and cis-stilbene epoxides (42a,b), while similar treatment of p-nitrobenzaldehyde with (40) produces 4,4'-dinitrostilbene (3e).Reaction of (8) with (40), as well as with (1), gives (9) and (10).The mechanism of formation of these products is discussed.