Hydrochloric Acid → 2-[N-(4,5-dimethoxy-2-hydroxybenzoyl)amino]-4-(ethoxycarbonyl)-1,3-thiazole

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Reaction Steps

A suspension (30 ml) of 2-[N-(2,4,5-trimethoxybenzoyl)amino]-4-(ethoxycarbonyl)-1,3-thiazole (10.0 g) in N,N-dimethylacetamide was allowed to dissolve with heat at a temperature of at least 150° C., and di-n-butylamine (8.8 g) was added dropwise to the solution, refluxed for 5 hours. The reaction mixture was allowed to cool, poured into a mixture of 1 N hydrochloric acid (100 ml) and ice water (100 ml), and further, water was added thereto. The crystals so precipitated were collected by filtration, washed with water, and then subjected to air drying and drying under reduced pressure to thereby obtain crude crystals (10.0 g). The crystals were followed by recrystallization from 1,4-dioxane, thereby 8.9 g of 2-[N-(4,5-dimethoxy-2-hydroxybenzoyl)amino]-4-(ethoxycarbonyl)-1,3-thiazole was obtained (yield: 82.3%).

Provenance & Evidence