Triethylamine → 1-[2(3,4-Dimethoxyphenyl) thiazol-4-ylcarbonyl]-2-methoxymethyl-4-(3,4,5-trimethoxybenzoyl)piperazine

Participants

Reaction Conditions

Reaction Steps

To a mixture of 2-methoxymethyl-4-(3,4,5trimethoxybenzoyl) piperazine hydrochloride obtained in Reference Example 6 (0.50 g), 2-(3,4-dimethoxyphenyl)thiazol-4-carboxylic acid (0.37 g), triethylamine (0.42 g) and N,N-dimethylformamide (5 ml) is added dropwise, while stirring under icecooling, diethyl cyanophosphonate (0.46 g). The reaction mixture is stirred at 0° C. for one hour and there poured into ice-water, followed by extraction with ethyl acetate. The organic layer is washed with water, dried and concentrated under reduced pressure. The concentrate is purified by means of a silica gel column chromatography (eluent: AcOEt) to give 1-[2(3,4-dimethoxyphenyl) thiazol-4-ylcarbonyl]-2-methoxymethyl-4-(3,4,5-trimethoxybenzoyl)piperazine. Recrystallization from EtOH gives colorless needles, m.p. 149-151° C.

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