2-Nitrobenzaldehyde → 2-Aminobenzaldehyde

o-(trifluoroacetamido)benzaldehyde (4). To a suspension of o-nitrobenzaldehyde (3 g, 19.86 mmol) in 35% aqueous hydrochloric acid (35 ml) was added 21 g (93.1 mmol) of tin (II) chloride in small portions. The suspension was stirred at room temperature for 72 h, neutralized with 6N aqueous sodium hydroxide and extracted with chloroform (4×50 ml). The combined chloroform layers were dried over sodium sulphate and evaporated, yielding 1.87 g (78%) of o-aminobenzaldehyde 3. A part of this residue (1.26 g, 10.4 mmol) was dissolved in dry ethyl ether (5 ml). This solution was cooled to 0° C. and treated dropwise with trifluoroacetic anhydride (2 ml, 14.15 mmol), while magnetically stirred. The solution was stirred for 2 h at room temperature. The solvent was evaporated and the residue was chromatographed on silica gel, eluting with a 7:3 petroleum ether-dichloromethane mixture. Yield, 1.65 g (77%) of compound 4.

1. extractionextracted with chloroform (4×50 ml)
2. dry with materialThe combined chloroform layers were dried over sodium sulphate
3. customevaporated

ORD record

ord-1a8f1d40318d4cf6bf69ebaec4c99ba4

Source dataset

uspto-grants-2003_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06656948B2