Yield: 99%

Reaction Conditions:

with sodium nitrite in ethanol;water at 0 - 60;

Steps:

B2.164.I Step-I: 2-Nitromalonaldehyde (intermediate B2-1)
Step-I: 2-Nitromalonaldehyde (intermediate B2-1) CHO OzN ^^CHO [00232] To a solution of 2,3-dibromo-4-oxobut-2-enoic acid (20 g, 78 mmol) in ethanol (30 mL), was added a solution of sodium nitrate (20 g, 235 mmol) in water (30.0 mL) at 0 °C. The reaction mixture was allowed to stir at 60 °C for 30 min. Then the reaction mixture was allowed to stir at room temperature for 1 h. The reaction mixture was cooled to 0 °C, at which point the solid was precipitated. The precipitated solid was filtered off and dried to afford the title compound as a yellowish solid (9.0 g, 99.0%). MS(ES): m/z 116.2 [M-H]^".

References:

BRISTOL-MYERS SQUIBB COMPANY;WASHBURN, William N.;MURUGAIAH SUBBAIAH, Murugaiah Andappan;AHMAD, Saleem WO2014/39412, 2014, A1 Location in patent:Paragraph 00232