o-Chloranil → Diethyl 2-(thiazol-2(3H)-ylidene)malonate
Reaction equation
C(OC([N:6]1[CH:10]=[CH:9][S:8][CH:7]1[CH:11]([C:17]([O:19][CH2:20][CH3:21])=[O:18])[C:12]([O:14][CH2:15][CH3:16])=[O:13])=O)C.ClC1C(=O)C(=O)C(Cl)=C(Cl)C=1Cl>ClCCl>[S:8]1[CH:9]=[CH:10][NH:6][C:7]1=[C:11]([C:17]([O:19][CH2:20][CH3:21])=[O:18])[C:12]([O:14][CH2:15][CH3:16])=[O:13]Participants
4
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Conditions
- Temperature
- 0 °C
Procedure
To a solution of the product of Example 44A (12.9 g, 40.7 mmoles) in dichloromethane (100.0 ml) was added tetrachloro-1,2-benzoquinone (10.0 g, 40.7 mmoles) in portions at about 0° C., such that the mixture always had time to decolorize to a yellow-orange color. The mixture was then stirred for about 1 hour at 0° C. and was then washed with saturated aqueous sodium bicarbonate solution (200.0 ml) and brine (100.0 ml). The organic layer was dried over MgSO4, filtered, concentrated in vacuum and the crude product was purified by flash column chromatography on silica gel using hexanes/ethyl acetate (2:1) as the mobile phase to provide the title compound.