Category: esters-buliding-blocks

These common heterocyclic compound, 24398-88-7, name is Ethyl 3-bromobenzoate, its traditional synthetic route has been very mature, but the traditional synthetic route has various shortcomings, such as complicated route, low yield, poor purity, etc, below Introduce a new synthetic route. 24398-88-7

General procedure: To an undivided electrochemical cell, fitted with an iron/nickel (64/36) rod as the anode and surroundedby a nickel foam as the cathode, were added DMF (50 mL), tetrabutylammonium bromide (1.2 mmol, 400mg), and 1,2-dibromoethane (2.5 mmol, 215 muL). The mixture was electrolyzed under argon at a constantcurrent intensity of 0.2 A at room temperature for 15 min. The current was then stopped, and the NiBr2bpycomplex (0.4 mmol, 150 mg), 3-amino- or 3-alkoxy/aryloxy-6-chloropyridazine (4 mmol), and aromatic orheteroaromatic halides (8 mmol) were sequentially added. The solution was electrolyzed at 0.2 A at roomtemperature until one of the starting materials was totally consumed. A saturated aqueous solution of EDTAsodium salt (100 mL) was added to the mixture, and the solution was extracted with dichloromethanecontaining 2-5% methanol (3 ¡Á 100 mL). The combined organic layers were dried over MgSO4, filtered,and evaporated under vacuum. The crude product was purified by flash chromatography on silica, elutedwith a gradient of solvents (pentane/acetone). For some polar cross-coupling compounds, a mixture ofacetone/methanol (95/5) was necessary.

Chemical properties determine the actual use. Each compound has specific chemical properties and uses. We look forward to more synthetic routes in the future to expand reaction routes of 24398-88-7.

Reference:
Article; Sengmany, Stephane; Sitter, Mathilde; Leonel, Eric; Le Gall, Erwan; Loirand, Gervaise; Martens, Thierry; Dubreuil, Didier; Dilasser, Florian; Rousselle, Morgane; Sauzeau, Vincent; Lebreton, Jacques; Pipelier, Muriel; Le Guevel, Remy; Bioorganic and Medicinal Chemistry Letters; vol. 29; 5; (2019); p. 755 – 760;,
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25597-16-4, A common heterocyclic compound, 25597-16-4, name is Ethyl 4,4,4-trifluorocrotonate, molecular formula is C6H7F3O2, its traditional synthetic route has been very mature, but the traditional synthetic route has various shortcomings, such as complicated route, low yield, poor purity, etc, below Introduce a new synthetic route.

The resulting product (0.45g, 1.9mmol) from step 4, ethyl 4,4,4-trifluorocrotonate (1.3g, 7.6mmol) and anhydrous potassium carbonate (2.6g, 1.9mmol) were dissolved in DMF (10mL), and then the system was stirred for 2hrs at 90C. At the end of reaction, the reaction system was cooled to room temperature and added with water, the mixture was extracted with ethyl acetate, and the organic phase was dried and evaporated in vacuum to obtain 0.40g of the product (55%) by column chromatography. 1HNMR (400 MHz, d-CDCl3), delta 7.88(s, 1H), 6.76 (s, 1H), 5.7(m, 1H), 4.3(dd, 2H),1.35(t, 3H) MS (MM-ES+APCI), m/z: 384 (M-H+)

The synthetic route of 25597-16-4 has been constantly updated, and we look forward to future research findings.

Reference:
Patent; Guangzhou Institute Of Biomedicine And Health, Chinese Academy Of Sciences; ZHANG, Yanmei; TALLEY, John Jeffrey; OBUKOWICZ, Mark G.; TU, Zhengchao; TORTORELLA, Micky; WANG, Yican; LIU, Jianqi; CHEN, Yan; LIU, Xiaorong; LU, Xin; EP2845854; (2015); A1;,
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3196-15-4, Name is Methyl 2-bromobutyrate, 3196-15-4, belongs to esters-buliding-blocks compound, is considered to be a conventional heterocyclic compound, which is widely used in drug synthesis. The chemical synthesis route is as follows.

Example 1. Synthesis of benzo bis-furan compound IV-1 (1) In a round-bottom flask equiped with a reflux condenser and a magnetic stirrer, 0.5135g (1.0mmol) of compound I dissolved in 10mL DMF and 0.346g (2.5mmol) potassium carbonate was added. The reaction was stirred at room temperature. After ten minutes, 0.272g (1.5mmol) 2-bromobutyric acid methyl ester VI-a-1 was added and stirring was continued for 5h. After completion of the reaction, 30mL of dichloromethane was added with copious amount of water (80mL¡Á5) until removal of DMF. The organic phase was seperated, dried over anhydrous magnesium sulfate, concentrated, and purified by TLC (E/P [ethyl acetate:petroleum ether] = 1:5) to give the benzofuran II-a-1. Yield 75%

Statistics shows that Methyl 2-bromobutyrate is playing an increasingly important role. we look forward to future research findings about 3196-15-4.

Reference:
Patent; Zhejiang University; Wang, Yuguang; Zhu, Bingchun; Liu, Juanfang; Li, Qingsi; (14 pag.)CN104016998; (2016); B;,
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Some common heterocyclic compound, 4341-76-8, name is Ethyl 2-butynoate, molecular formula is C6H8O2, traditional synthetic route has been very mature, but the traditional synthetic route has various shortcomings, such as complicated route, low yield, poor purity, etc, below Introduce a new synthetic route. 4341-76-8

General procedure: In a two neck rbf was stirred a mixture of Pd(OAc)2 (275 mg,1.22 mmol) and TDMPP (540 mg, 1.22 mmol) in benzene (30 ml)for 15 min at rt under nitrogen. To this mixture was added ethyl-2-butynoate 7 (2.84 ml, 24.48 mmol) and the resulting mixturewas further stirred for 10 min at rt. Next, ethynylbenzene 4a(2.50 g, 24.48 mmol) was added to this solution and the mixturewas stirred for 5-10 min until reaction was completed. Theworkup of reaction was performed by evaporating the solvent invacuum followed by column chromatography (Hexane:EtOAc = 100:1) to give the desired compound 8a (2.62 g);

These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 4341-76-8, its application will become more common.

Reference:
Article; Singh, Sarbjit; Goo, Ja-Il; Noh, Hyojin; Lee, Sung Jae; Kim, Myoung Woo; Park, Hyejun; Jalani, Hitesh B.; Lee, Kyeong; Kim, Chunsook; Kim, Won-Ki; Ju, Chung; Choi, Yongseok; Bioorganic and Medicinal Chemistry; vol. 25; 4; (2017); p. 1394 – 1405;,
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The chemical industry reduces the impact on the environment during synthesis 139102-34-4, name is Methyl 4-bromo-2-methoxybenzoate, I believe this compound will play a more active role in future production and life. 139102-34-4

Preparation of Example 389; Step i:; To methyl-4-bromo-2-methoxybenzoate (Aldrich) (1.0 g, 4.1 mmol) in THF(10 ml_), was added LiBH4 (0.13 g, 6.1 mmol). Ethanol (2 mL) was added dropwise. The resulting reaction mixture was stirred at room temperature for 20 h. 1 N NaOH was added, and the mixture was extracted with EtOAc. The organic layers were combined and washed with water and brine, then dried (MgSO4), filtered, and concentrated in vacuoXo provide the corresponfing benzyl alcohol (0.86 g, 4.0 mmol).

The chemical industry reduces the impact on the environment during synthesis 139102-34-4. I believe this compound will play a more active role in future production and life.

Reference:
Patent; SCHERING CORPORATION; WO2006/60461; (2006); A1;,
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A common heterocyclic compound, 35180-01-9, name is Chloromethyl isopropyl carbonate, molecular formula is C5H9ClO3, its traditional synthetic route has been very mature, but the traditional synthetic route has various shortcomings, such as complicated route, low yield, poor purity, etc, below Introduce a new synthetic route. 35180-01-9.

S03 condensation: After pretreating the crude tenofovir obtained in the step S02, and stirring 16 L of N-methylpyrrolidone and 4.44 kg of triethylamine, the temperature is raised to 50 C and stirred.11.15 kg of isopropyl chloromethyl carbonate was added dropwise, stirred, and the reaction was completely cooled and quenched.After cooling, add 12 L of cyclohexane twice, stir, centrifuge, layer, and discard the upper layer of cyclohexane. The lower layer of the filtrate was transferred to a reaction kettle, and 30 L of water and 20 L of ethyl acetate were added.After stirring for 30 minutes, the layers were allowed to stand, and the aqueous layer was extracted with 10 L of ethyl acetate.Wash with 20L of 10wt% brine, add 1.0kg anhydrous sodium sulfate, stir dry, centrifuge,The filtrate is transferred to the transfer reactor in batches, concentrated under reduced pressure, and the concentrate is transferred to the reaction vessel.Denotefovir dipivoxilCrude.

The synthetic route of Chloromethyl isopropyl carbonate has been constantly updated, and we look forward to future research findings.

Reference:
Patent; Shandong Kexing Biological Products Co., Ltd.; Hao Zhihai; Wang Cuicui; Lu Fuxin; Guo Chao; Wang Jun; Zhang Yun; Qiu Duxian; Cui Ning; (26 pag.)CN108409789; (2018); A;,
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2555-28-4,Some common heterocyclic compound, 2555-28-4, name is 7-Methoxy-4-methylcoumarin, molecular formula is C11H10O3, traditional synthetic route has been very mature, but the traditional synthetic route has various shortcomings, such as complicated route, low yield, poor purity, etc, below Introduce a new synthetic route.

(0.95 g, 5 mmol) of 4a, 50 mL of xylene was added to a round bottom flask,Stir and heat, so that it gradually dissolved.Then, selenium dioxide (0.55 g, 5 mmol) was added and the reaction was refluxed for 12 h.Stop heating, hot suction filter, the filtrate cold with yellow solid precipitation, The filtrate was concentrated under reduced pressure to give a yellow solid 4b (0.85 g, yield 84%).

These compound has a wide range of applications. It is believed that with the continuous development of the source of the synthetic route 2555-28-4, its application will become more common.

Reference:
Patent; Shandong He Bentang Biological Technology Co., Ltd.; Pan Xuan; Zhang Chengrui; Wang Huili; (9 pag.)CN106317029; (2017); A;,
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4131-74-2, In the chemical reaction process, reaction time, type of solvent, can easily affect the result of the reaction, thereby determining the yield and properties of the reaction product. An updated downstream synthesis route of 4131-74-2 as follows.

26.16g (0.1411 mol) of octadecylamine was added to a 250 ml reaction flask, followed by addition of 100ml of high-boiling petroleum ether (90-120 C) or toluene or ethanol, 1-10% (molar ratio) of p-toluenesulfonic acid or hydrochloric acid or acetic acid or hydrochloric acid and 10g (0.04848 mol) of intermediate of product V. Placed in a constant temperature oil bath pot and stirred the reaction temperature was set at 125 , nitrogen protection plus condensate trap. (Time to complete the reaction time is about 36-48 hours, with increasing temperature the reaction flask to dissolve the solid into a liquid, when the end of the reaction, the flask was cooled to room temperature, the liquid into a solid whole. To the reaction flask with stirring adding an appropriate amount of methanol, and then subjected to suction filtration, washed with methanol 2-4 times, after heating to 40 degrees Celsius drained and dried under vacuum to give a white solid, yield 86-97%.

At the same time, in my other blogs, there are other synthetic methods of this type of compound, 4131-74-2, and friends who are interested can also refer to it.

Reference:
Patent; Shaoxing Ruikang Biotechnologies Co., Inc.; Mao, Lijuan; Liu, Shubai; Wang, Songping; Zhang, Zaixian; Wan, Dingfei; Peng, Chuanyang; Ding, Yifan; Sun, Xing; (21 pag.)CN105693545; (2016); A;,
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10601-80-6, Each compound has different characteristics, and only by selecting the characteristics of the compound suitable for a specific situation can the compound be applied on a large scale. 10601-80-6, name is Ethyl 3,3-diethoxypropionate, This compound has unique chemical properties. The synthetic route is as follows.

Example 25 Preparation of 3,3-diethoxypropanoic acid Ref. . To a 250 mL round-bottomed flask with magnetic stirring that contained ethyl 3,3-diethoxypropanoate (20.0 g, 102.0 mmol, colourless oil, 97 %), a previously prepared solution of NaOH (5.23 g, 131.0 mmol) in H2O (30 mL) was added. The resulting mixture was stirred to reflux (100 C) during 1h. After allowing it to temper, the mixture was acidified using HCl 37 % and it was extracted with AcOEt, 8x 20 mL. The resulting organic phase was washed with 1x 20 mL NaCl sat., dried with Na2SO4, filtered and concentrated to dryness. The obtained oil was confirmed to correspond to the title compound (15.9 g, 98.0 mmol, 96 %).

If you are interested in these compounds, you can also browse my other articles.Thank you for taking the time to read this article. I hope you enjoyed it.

Reference:
Patent; Esteve Quimica, S.A.; EP2418192; (2012); A1;,
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

178312-47-5, name is Ethyl 4,4-difluorocyclohexanecarboxylate, belongs to esters-buliding-blocks compound, is considered to be a conventional heterocyclic compound, which is widely used in drug synthesis. The chemical synthesis route is as follows. 178312-47-5

To a reaction mixture of 4,4-difluorocyclohexanecarboxylic acid ethyl ester (7.1 g, 37 mmol) in THF (50 mL) cooled to 0 C. was added dropwise 2.0 M lithium tetrahydroaluminate in THF (18.5 mL) over 10 min. The reaction mixture was stirred at 0 C. for 1 h. Water (5 mL) was added dropwise, followed by 1.0N NaOH (5 mL). The reaction mixture was filtered through Celite, THF was evaporated, and the resulting aqueous solution was diluted with brine (50 mL) and extracted with ethyl acetate (50 mL). The organic layer was collected, dried over anhydrous sodium sulfate, filtered, and concentrated to give the title compound as a clear oil (5.6 g) which was used without further purification.

Statistics shows that 178312-47-5 is playing an increasingly important role. we look forward to future research findings about Ethyl 4,4-difluorocyclohexanecarboxylate.

Reference:
Patent; Saito, Daisuke Roland; Long, Daniel D.; Van Dyke, Priscilla; Church, Timothy J.; Jlang, Lan; Frieman, Bryan; US2009/62333; (2009); A1;,
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Ester – an overview | ScienceDirect Topics