Sodium ethoxide → Diethyl 2-dimethylamino-5-(4-methylbenzylthio)-2,4-hexadienedioate

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Reaction Steps

The procedure is as in Example 2 for the preparation of diethyl 2-dimethylamino-5-phenylthio-2,4-hexadienedioate, starting with N-(3-dimethylamino-3-ethoxycarbonylpropenylidene)-N-methylmethanaminium tetrafluoroborate (5.7 g), a 2M ethanolic solution of sodium ethylate (10 cc) and ethyl (4-methylbenzylthio)acetate (4.5 g) in ethanol (50 cc). After purification by chromatography on a silica column with a mixture of cyclohexane and ethyl acetate (50:50 by volume) as eluent, diethyl 2-dimethylamino-5-(4-methylbenzylthio)-2,4-hexadienedioate (5 g) is obtained in the form of a yellow oil, and is used in the crude state in the subsequent syntheses.

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