5-NITRO-1,3-BENZOXAZOLE

General procedure: A 50-mL, one-necked, round bottomed flask equipped with a magnetic stir bar was charged with the corresponding 2-aminophenol derivative (5.0 mmol, 1.0 equiv) and triethyl orthoformate (60.0 mmol, 12.0 equiv). The reaction mixture was carefully heated to 150 °C for 6 h. Upon completion, the reaction mixture was cooled to room temperature and the excess orthoformate and ethanol byproduct were removed from the residue under reduced pressure. The crude product was further purified by silica gel (SiOGeneral procedure: To a mixture of orthoester (1.1 mmol) and o-aminophenol or o-aminothiophenol (1 mmol) was added TSA (1 molpercent). The mixture was stirred at 80–90 °C for the appropriate time according to Table 4. After the completion of the reaction (as indicated by TLC), the mixture was diluted with chloroform (10 mL) and the catalyst was separated by filtration. Further purification was achieved by column chromatographyGeneral procedure: A mixture of 2-aminophenol derivative (5 mmol) and triethyl orthoformate (15 mL) was heated at reflux for 4 h. After cooling to room temperature, remained triethyl orthoformate was removed under reduced pressure and the residue was purified by column chromatography on silica gel.A solution of 2-amino-4-nitrophenol (600 mg, 3.9 mmol) in trimethyl orthoformate (30 ml)was stirred at reflux for 12 hours_ The reaction mixture was slowly poured into ice-coldwater (100 ml)and extractedwith ethyl acetate (100 ml). The organiclayer was concentrated under reduced pressureand the residue 10 was purified by silica gel column chromatography eluting with dichloromethane: methanol=301to afford 5-nitrobenzo[d]oxazole as a white solid (530 mg, 83percent).LCMS (ESI):mlz = 164.0 [M+H(

Molecular Weight:164.12
XLogP3:1.4
Hydrogen Bond Acceptor Count:4
Exact Mass:164.02219199
Monoisotopic Mass:164.02219199
Topological Polar Surface Area:71.8
Heavy Atom Count:12
Complexity:192
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes