Researchers who often do experiments know that organic synthesis is a process of preparing more complex target molecules from simple raw materials through one or more chemical reactions. Generally, it requires fewer steps, and cheap raw materials. 1731-79-9, name is Dimethyl dodecanedioate, A new synthetic method of this compound is introduced below., SDS of cas: 1731-79-9
1,12-dodecanedioic acid dimethyl ester (1000.0g, 3.87 mols) was put into a reactor, heated and stirred under a reduced pressure of 80kPa at 105C. Methanol was distilled off while the mixture of gamma-butyrolactone (83.3g, 0.97 mol) and 28% by weight of sodium methoxide solution in methanol (186.7g, 0.97 mols) prepared at the room temperature was dropped into the heated 1,12-dodecanedioic acid dimethyl ester in 30 minutes. After continuing the reaction for 30 minutes then, the pressure was reduced to 26.7 kPa to further continue the reaction for 240 minutes. Next, after returning to ordinary pressure, the reactant was cooled to 70C and, while being stirred, methyliodide (137.7g, 101.6 mols) was dropped into it in 30 minutes. N-hexane (700g) and, next, water (3009) were poured into it. After removing the water layer, it was washed with aqueous solution of 10% sodium hydroxide (150g: twice) and water (200.0g: twice). N-hexane was distilled off under a reduced pressure. The remained oily substance was subjected to a distillation under a reduced pressure (oil bath temperature 200C/60 to 130Pa) and excessive 1,12-dodecanedioic acid dimethyl ester was distilled off. 762.9g of a distilled substance and 264.2g of a distillation residue were obtained. As a result of an analysis of the distillation residue by gas chromatography, it was found that 80.7% by weight of the compound indicated by the general formula (2) (n = 10, R = Me) was contained. This was mixed with aqueous solution of 10% sodium hydroxide (675g) and heated/refluxed for 5.5 hours. After diethylene glycol (230g) and 60% hydrazine monohydrate (124g) were added to the reaction liquid and stirred for one hour at 110C, the temperature of the reaction system was elevated to 170 to 200C while removing water, and after aqueous solution of 30% sodium hydroxide (100g) was dropped into it in 4 hours, it was stirred for 6 hours at that temperature. While pouring water (930g) into it, it was cooled, and with addition of diluted sulfuric acid it was extracted with toluene. After the organic layer was washed with water, the solvent was removed under a reduced pressure, and 254g of a crystalline residue containing 13-methyl-15-hydroxypentadecanoic acid (n = 10) as the main component was obtained. This was cyclized by intramolecular ester interchange reaction to thereby obtain 80.7g of a cyclic compound. This contained 98.9% by weight of 13-methyl-15-pentadecanolide. The yield was 32 mol%/butyrolactone. 1H-NMR(CDCl3,400MHz) 4.16(2H)m; 2.32(2H)m; 0.90(3H)d J=6.4Hz 13C-NMR(CDCl3) 173.89; 61.86; 35.31; 34.49; 34.20; 30.82; 27.68; 27.25; 26.57; 26.42; 26.26; 26.10; 25.87; 24.89; 24.52; 19.51 IR(film) 2930; 2860; 1740; 1460; 1350; 1245; 1173; 1115 MS 254(5); 236(9); 225(11); 207(21); 111(16); 97(35); 83(42); 70(100); 55(68); 41 (40)
The basis of chemical reaction formula synthesis, the synthesis route is composed of some specific reactions and combined according to certain logical thinking. We look forward to the emergence of more reaction modes in the future.
Reference:
Patent; SODA AROMATIC COMPANY, LIMITED; EP1741706; (2007); A1;,
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