Triethylamine → 2-Methoxymethyl-1-[2-(3-pyridyl) thiazol-4-ylcarbonyl]-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 (0.52 g), 2-(3-pyridyl)thiazol-4-carboxylic acid (0.3 g), triethylamine (0.46 g) and N,N-dimethylformamide (3 ml) is added dropwise, while stirring under icecooling, diethyl cyanophosphonate (0.47 g). The reaction mixture is stirred at 0° C. for one hour, and then 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-CH2Cl2 --CH3OH=10:9:1) to give 2-methoxymethyl-1-[2-(3-pyridyl) thiazol-4-ylcarbonyl]-4-(3,4,5-trimethoxybenzoyl) piperazine. Recrystallization from ethanol gives colorless needles m.p. 149-150° C.

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