Rearrangement on Deoxygenation of Nitrosobenzene

Photoisomerization of 3H -Azepines

“…A number of 2-substituted 3H-azepines were known when our investigation was initiated. 27,28,33 We were particularly interested in the photochemistry of 2-dimethylamino-3H-azepine, 28 2-amino-3H-azepine 27 and 2-ethoxy-3H-azepine. Our studies showed that these compounds underwent selective photoelectrocyclization to 3-substituted 2-azabicyclo[3.2.0]hepta-2,6-dienes.…”

One-pot Synthesis of 2-Substituted 4H-Chromeno[3,4-d]oxazol-4-ones from 4-Hydroxy-3-nitrocoumarin and Acids in the Presence of Triphenylphosphine and Phosphorus Pentoxide under Microwave Irradiation

“…Triphenylphosphine (PPh 3 ) is a versatile reagent for the reduction of a range of substrates including azides 32 (Staudinger reaction), disulfides, 33 sulfonyl chloride, 34 peroxides, 35 ozonides, 36 nitro compounds (for the Cadogan type reductive cyclization), 37 nitroso compounds, 38 and Noxides. 39 In a continuation of our studies on fused oxazolocoumarin derivatives, 1d, 30,31 we would like to present, herein, the use of PPh 3 for the one-pot synthesis of fused oxazolocoumarins from o-hydroxynitrocoumarin in the presence of acid and phosphorus pentoxide.…”

Acid-promoted nucleophilic aromatic substitution in deoxygenation of nitro and nitroso compounds

“…Chromatography of the acid-soluble material gave o-toluidine (2%) followed by diethyl 2-amino-3-methylphenylphosphonate (11, 2%) purified by bulb-to-bulb distillation: nmr (CC14) 7.0-7.4 (overlapping doublet and doublet of doublets, 7.05 d, Jh-h = 8 Hz, 7.0-7.4, d of d, Jh-h = 8, JP-H =' 14 Hz, 2), 6.5 (six-line m, Jh-h " 8, Jh-h ~Jp-H -4. Hz, 1), 5.37 (br s, 2), 4.0 (quintet, 4), 2.10 (s, 3), 1.28 (t, 6). There was also eluted diethyl 4-amino-3-methylphenylphosphonate (12, 10%): mp 81-83°after recrystallization from ether-hexane; nmr (CC14) 7.1-7.7 (d at 7.50, JP_H = 13 Hz, overlapping m, 2), 6.72 (d of d, Jh-h s 8, JH_P = 4 Hz, 1), 4.45 (s, 2), 4.08 (quintet, 4), 2.12 (s, 3), 1.30 (t, 6).…”