4-Hydroxy-3-nitrophenylacetic

Tesaki, S., Tanabe, S., Ono, H., Fukushi, E., Karawabata, 1., Watanaba, M. 4-Hydroxy-3-nitrophenylacetic and ainapic acids as antibacterial compounds from mustard seeds. Ipn. Soc. Biosci. Biotech. Agrochem. 62(5), 998-1000 (1998)... 

Methyl-4-hydroxy-3-nitrophenylacetic acid. The acid (7.5g) was dissolved in 250 ml CH- jOH, the solution saturated with HCl and stirred for 2 h. Rotary evaporation gave a yellow solid which was recrystallized from CH3OH to give yellow needles (6.4g, 80%) m.p. 67-68° (lit. m.p. (19) 68-69°). 

Rankin LD, Bodenmiller DM, Partridge JD, Nishino SF, Spain JC, Spiro S (2008) Escherichia coli NsrR regulates a pathway for the oxidation of 3-nitrotyramine to 4-hydroxy-3-nitrophenylacetate. J Bacteriol 190 6170-6177... 

The intermediacy of an aci-nitro compound has been proposed for the sulfuric acid cyclization of o-nitrophenylacetic acid to yield a mixture of 2,1-benzisoxazole and 2,1-benzisoxazole-3-carboxylic acid. The acid does not decarboxylate under the reaction conditions. The proposed aci-nitro intermediate cyclized to an A/ -hydroxy compound which decomposed to the products (Scheme 179) (70JCS(C)2660). 

The reductive cycbzation of o-nitrophenylacetic acids or esters gives oxyindoles, which has been applied to preparation of 6-hydroxy-7-methoxyoxyindole in a synthesis of (+)-paraher-quamide B (Scheme 10.11).42... 

Reduction of2-nitrophenylacetic acids. The best method of preparing l-hydroxy-2-oxindole is the reduction of methyl 2-nitrophenylacetate (169) with zinc and ammonium chloride and immediate acetylation... 

Condensations of aryiacetic acids, arylacetates and arylacetonitriles with aromatic aldehydes and ketones proceed under standard Knoevenagel conditions, providing access to stilbenes or substituted stil-benes. - Thus 3-nitrobenzaldehyde and 4-nitrophenylacetic acid react in the presence of different amines to give (130), (131) and (132). The ratio of the products varies greatly with the amine used. (131) and (132) could easily be transformed into (130) in high yield. Reaction of arylacetates with o-hydroxybenzaldehydes yields the corresponding coumarins. The condensation of 2-hydroxy-4-meth-oxybenzaldehyde (133) with pyridylacetates like (134) yields 7-methoxy-3-pyridylcoumarins like (135) (Scheme 20). 

Photodecarboxylation of the dissociated form of a-hydroxy-substituted arylacetic acids and related substrates occurs from the singlet excited state (SJ and leads to the corresponding benzyl alcohols with high quantum yields (O = 0.2 to 0.7) via a heterolytic mechanism (Scheme 2). Photodecarboxylation of some diarylacetic acids (Scheme 2) also proceeds from Sj via heterolytic mechanism. It is remarkable that these compounds show dramatic differences in their relative photodecarboxylation efhciency (O = 0.04 to 0.6). The reaction is enhanced when a cyclic delocalized carbanion with 4n electrons is formed. By contrast, photodecarboxylation of m- and p-nitrophenylacetic acids in aqueous solutions occurs via a heterolytic mechanism from Tj." The photodecarboxylation of pyruvic and benzoylformic acids takes place with high quantum yields ( 5 > 0.6) in aqueous solutions, to give acetaldehyde and benzaldehyde, respectively as the primary photoproducts. On the other hand, 2-, 3-, and 4-pyridinylacetic acids undergo photodecarboxylation in aqueous solutions via a heterolytic mechanism from their zwitterionic forms. 

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