* All experimental methods are cited from the reference, please refer to the original source for details. We do not guarantee the accuracy of the content in the reference.
Reference:
[1] Chemische Berichte, 1955, vol. 88, p. 370,373
2
[ 99365-39-6 ]
[ 52415-29-9 ]
Reference:
[1] Chemische Berichte, 1955, vol. 88, p. 370,373
3
[ 99365-39-6 ]
[ 16732-65-3 ]
Reference:
[1] Journal of the Chemical Society, 1954, p. 3403,3406
[2] Chemische Berichte, 1955, vol. 88, p. 370,373
[3] Journal of the Chemical Society, 1954, p. 3403,3406
4
[ 99365-39-6 ]
[ 103858-53-3 ]
Reference:
[1] Chemische Berichte, 1955, vol. 88, p. 370,373
5
[ 99365-39-6 ]
[ 6127-11-3 ]
Reference:
[1] Chemical and Pharmaceutical Bulletin, 1985, vol. 33, # 4, p. 1414 - 1418
[2] Patent: US6268391, 2001, B1,
With sodium hydroxide; dihydrogen peroxide; In water;
Example 133b 4-bromo-2-nitrophenylacetic acid A 30% hydrogen peroxide solution (4.95 mL, 0.04 mol) was added dropwise to a solution of 4-bromo-2-nitrophenylpyruvic acid (0.04 mol) and sodium hydroxide (5.3 g 0.1 mol) in water (175 mL) stirring at 0 C. The reaction solution was stirred for 1 h at 5 C. and then acidified with dilute HCl. The yellow precipitate was filtered and the crude product recrystallized from hexane and ethyl acetate to yield 8.4 g (75%) as a light beige solid; 1H-NMR (DMSO-d6): delta12.67 (br s, 1H), 8.28 (d, J=2.0 Hz), 7.97 (dd, 1H, J=9.0 Hz, 2.0 Hz), 7.55 (d, 1H, J=8.0 Hz 4.00 (s, 3H). MS (-ve) m/z: 259 (M-H).
General procedure: 1mmol of the required pyruvic acid, 5, or 2-hydroxyacrylic acid,4, was dissolved in 2mL of 5% acetic acid/ethanol, then 1equiv. of <strong>[312303-66-5]4-(3,4-dichloro-phenyl)-thiazol-2-yl-hydrazine</strong>, 9 (1.0mmol, 259mg) was added. The reaction mixture was heated to 90C and stirred for 1h. Then it was cooled to 0C. The produced precipitate was filtered and washed with cold water then dried under vacuum. The products were obtained as mixture of E/Z isomers, which were separated using reversed phase column chromatography using gradual increase of methanol in water containing 0.1% of formic acid as eluent.