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ChemicalBook CAS DataBase List 1-(2,2-diMethoxyethyl)-5-Methoxy-6-(Methoxycarbonyl)-4-oxo-1,4-dihydropyridine-3-carboxylic acid
1335210-23-5

1-(2,2-diMethoxyethyl)-5-Methoxy-6-(Methoxycarbonyl)-4-oxo-1,4-dihydropyridine-3-carboxylic acid synthesis

5synthesis methods
N, N-Dimethylformamide dimethyl acetal was added to methyl 4-methoxy-3-oxobutanoate, and the mixture was kept for 2 h at 25-30°C. The resulting methyl2-(dimethylaminomethylidene)-4-methoxy-3-oxobutanoate was dissolved in methanol, 2-amino acetaldehyde dimethyl acetal was added, and the mixture was stirred at20-30°C for 2 h. The solvent was removed under reduced pressure, the residue was diluted with methanol, and dimethyl oxalate was added at 25-30°C. The mixture was cooled to 0-5°C, 30 wt % sodium methoxide in methanol was slowly added, and the mixture was slowly heated to 40°C, stirred for 14 h at that temperature, and concentrated under reduced pressure. The residue was diluted with dichloromethane and poured into cold (0-5°C)2 N aqueous HCl. The organic phase was separated, the aqueous layer was extracted with dichloromethane (2× ), and the combined organic layers were washed with demineralized water and concentrated under reduced pressure at 40-45 °C to obtain intermediate. The product was dissolved in methanol, the solution was cooled to 0-5°C, and lithium hydroxide monohydrate was added. The mixture was stirred at 0-5°C for 3 h, quenched with 2 N aqueous HCl, and extracted with ethyl acetate (3×). Finally, the product 1-(2,2-diMethoxyethyl)-5-Methoxy-6-(Methoxycarbonyl)-4-oxo-1,4-dihydropyridine-3-carboxylic acid can be obtained through further purification.
1-(2,2-diMethoxyethyl)-5-Methoxy-6-(Methoxycarbonyl)-4-oxo-1,4-dihydropyridine-3-carboxylic acid
-

Yield:-

Reaction Conditions:

Stage #1: Dimethyl oxalate;methyl 2-(((2,2-dimethoxyethyl)amino)methylene)-4-methoxy-3-oxobutanoatewith lithium hydride in methanol at -25 - 40; for 14 h;
Stage #2: with methanol;lithium hydroxide at -5 - 5; for 1 h;
Stage #3: with hydrogenchloride in methanol;water at -5;

Steps:

A

A. l-[2,2-Bis(methyloxy)ethyl]-5-(methyloxy)-6-[(methyIoxy)carbonyl]-4-oxo-l,4-dihydro- 3-pyridinecarboxylic acidA mixture of methyl 4-methoxyacetoacetate (20 mL) and DMFDMA (24 mL) was stirred at room temperature for 1.5 h. The reaction mixture was diluted with MeOH (50 mL) and aminoacetaldehyde dimethyl acetal (16.7 mL) was added. The mixture was stirred for 1 h at room temperature, concentrated, and then diluted with MeOH (113 mL). Dimethyl oxalate (45.66 g) was charged followed by portion-wise addition of LiH (2.15 g) while maintaining the reaction temperature below 25 °C. The reaction content was heated to 40 °C for 14 h. The reaction mixture was cooled to -5 °C and LiOH (14.82 g) was added while maintaining the reaction temperature below 5 °C. When addition was complete, the mixture was stirred for a further 2 h at 3-5 °C for 1 h. The reaction mixture was quenched with aqueous HC1 (2 N, 367 mL), maintaining the reaction temperature below 5 °C. When addition was complete, EtOAc (450 mL) was added and the mixture was warmed to 20 °C. The reaction mixture was filtered and the aqueous layer discarded. Water (225 mL) was added and the organic layer was removed under reduced pressure. The product was collected by filtration and dried in a vacuum oven overnight at 50 °C. The product was obtained as a solid.

References:

WO2011/119566,2011,A1 Location in patent:Page/Page column 8

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