
首页

产品搜索
|
产品推荐:911466-96-1(2,4-噻唑二羧酸 2-乙酯)
名称:2,4-噻唑二羧酸 2-乙酯 英文名称:2,4-Thiazoledicarboxylic acid,2-ethyl ester 分子式:C7H7NO4S分子量: 201.2 Cas No.:911466-96-1 结构式: 规格:95% 外观:棕色固体 用途:基础原料、有机中间体、医药中间体 合成工艺如下: 1,4-dioxane; Reactants are commercially availlable. SCHERING CORPORATION, WO2008/54702, A1, (2008) EXAMPLE 32Preparation of Intermediate Compound 32AA mixture of 3-bromopyruvic acid (16.37 g, 98.05 mmol) in anhydrous dioxane (90 ml_) was treated with ethyl thioamidooxalate (13.08 g, 98.22 mmol) for 1.2 h at 50 0C, and was then concentrated at 50 0C to yield a dry yellow solid. The crude product was dissolved in saturated sodium bicarbonate (150 mL) and water (150 mL). This solution was extracte d with ethyl acetate (6 x 400 mL). The aqueous EPO layer was then acidified to pH 2 with concentrated aqueous HCI (21 ml_), resulting in the formation of a heavy precipitate. This suspen sion was extracted with ethyl acetate (5 x 500 ml_). These extracts were pooled, dried with sodium sulfate, filtered, concentrated, and dried for about 15 hours under vacuum to yield compound 32A as a red-brown solid (14.36 g, 73percent yield) which was used without further purification.
|
|