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ChemicalBook CAS DataBase List 4-Pyrimidinecarboxylic acid
31462-59-6

4-Pyrimidinecarboxylic acid synthesis

9synthesis methods
-

Yield:31462-59-6 80.5%

Reaction Conditions:

with selenium(IV) oxide in pyridine at 20 - 80; for 5.5 h;

Steps:

20 Example 20: Synthesis of (2-Amino-5-chloro-phenyl)-pyrimidin-4-yl-methanone

To 4-Methyl pyrimidine (5.0 g, 0.053 mol) in pyridine (55ML) was added selenium dioxide (8.82 g, 0.079 mol) at RT with stirring. The reaction mixture was stirred at 55 °C for 2 h and at 80 °C for 3.5 hr. After cooling to RT and stirring over night, the reaction mixture was filtered and the residue was washed with pyridine. The combined pyridine solution was concentrated and the carboxylic acid obtained was washed with water to remove traces of selenium dioxide. Yield : 5.3 g, 80.5 %. [00157] To Pyrimidine-4-carboxylic acid (5.0 g, 0.04 mol) in methanol (170 ml) was added conc. HCI (2 ML) at RT. After refluxing overnight, the reaction mixture was cooled to RT and neutralized with 10 % sodium bicarbonate solution and concentrated. The ester was extracted with diethyl ether, dried over NA2SO4 AND concentrated to get the methyl ester as a yellow solid, yield : 3.3 g, 57.55 %. [00158] TRIMETHYL ACETYLCHLORIDE (11.30 g, 0.093 mol) was added to a benzene (500 ML) solution of triethylamine (15.75 g, 0.155 mol) and 4- CHLOROANILINE (10.0 g, 0.078 mol) at 0°C. The reaction mixture was warmed to RT and stirred for 3h. The reaction mixture was then quenched with water, extracted with ethyl acetate, washed with water, brine solution and dried over NA2SO4. The solid product obtained was crystallized from pet ether. Yield : 14.0 g, 84. 43 %. [00159] To N- (4-chlorophenyl)-2, 2-dimethyl propanamide (3.5 g, 0.0165 mol) in THF (50 MI) at 0 °C was added n-butyl lithium in hexane (2.64 g, 1.2 M, 0. 041 MOL). Stirring was continued at 0 °C for 2 h, the reaction then cooled to-70 °C, pyrimidine-4-methyl carboxylate (3.18 g, 0.023 mol) in THF (25 ML) was then added slowly and the solution was warmed to RT and stirred overnight. Diethyl ether (50 ml) and water (50 ml) were added and the organic layer was separated. The aqueous layer was further extracted with ether. The combined ether layers were washed with water, brine and dried over NA2SO4. The product obtained upon concentration was purified by column chromatography. Yield : 1.7 g, 32.69 %. [00160] The protected amino ketone (1.7 g, 0.0054 mol) in sulfuric acid (10 ML, 70 %) was heated at 95 °C over night. The reaction mixture was cooled to RT and basified with 10% NAOH, extracted with DCM, washed with water, brine and dried over NA2SO4. The product obtained upon concentration was purified by column chromatography using basic alumina to yield title compound (0.20g, 16%).

References:

WO2004/46092,2004,A2 Location in patent:Page 52-53

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