Discovery of 25542-62-5

At the same time, in my other blogs, there are other synthetic methods of this type of compound, Ethyl 6-bromohexanoate, and friends who are interested can also refer to it.

Reference of 25542-62-5, As we all know, there are many different methods for the synthesis of a compound, and people can choose the synthesis method that suits their own laboratory according to the actual situation. 25542-62-5 name is Ethyl 6-bromohexanoate, This compound is widely used in many fields, so it is necessary to find a new synthetic route. The downstream synthesis method of this compound is introduced below.

Reactions were carried out in a Biotage Initiator 60 Microwave Reactor, employing the 20mL process-scale reactor vials. Thirteen (13) identical reactions at the 10 mmol scale were setup in parallel and processed in serial, as follows: All three (3) reagents and reaction solvent were added to the MW vial in the following sequence; (1) ethyl-bromo-hexanoate (1.77 mL), (2) salicylaldehyde (1.05 mL), (3) cesium carbonate (CS2CO3) (3.91 g) and (4) reaction solvent DMA (17.18 mL). Care was taken to dispense the N-N-dimethylacetamide (DMA) solvent in such a manner so as to wash down the vial walls of reactant or solid base. To each vial was added a magnetic stir bar and fitted with a crimp seal cap and adapter collar. The reactions were than process in the MW Reactor for 10 minutes (at temperature) at 140 C with mixing. Following standard ramp up, fixed hold time at temperature and cool down, samples were kept sealed at ambient temperature until the entire lot was processed. The reaction mixtures were combined and transferred to a 2L separatory funnel. Vial contents were washed with ethyl acetate (EtOAc), and a total EtOAc layer of about 800 mL was added. To this was added 800 mL of 1.0 N NaOH solution, and the two layers were vigorously shaken and mixed and then separated. The NaOH aqueous layer was back-extracted 3 x 250 mL with EtOAc, and all the organic layers were combined (about 750 mL) and washed with 800 mL of 1.0 M citric acid solution. The citric acid layer was again back extracted with EtOAc (3 x 250 mL), and the organic layers were again combined (about 1.5 L) and washed (3 x 500 mL) with brine (saturated NaCl), dried over sodium sulfate (Na2SO t) and concentrated to dryness in vacuo. Silica gel TLC (3: 1 Hexanes-EtOAc) Rf = 0.34 (product), Rf = 0.45, 0.25 (trace impurities). Theoretical yield = 13 x 2.64 g or 34.32 g (130 mmol). Isolation and Observed yield = 33.30 g, (33.30 g/34.32 g x 100) = 97%. NMR (, 13C, COSY) and LCMS (ESI+/-) conform to structure.

At the same time, in my other blogs, there are other synthetic methods of this type of compound, Ethyl 6-bromohexanoate, and friends who are interested can also refer to it.

Reference:
Patent; SALK INSTITUTE FOR BIOLOGICAL STUDIES; MITOKYNE, INC.; EVANS, Ronald; BAIGA, Thomas, J.; BOCK, Mark, G.; DOWNES, Michael; EMBLER, Emi, Kanakubo; FAN, Weiwei; KEANA, John, F.W.; KLUGE, Arthur, F.; NOEL, Joseph, P.; PATANE, Mike, A.; WO2014/165827; (2014); A1;,
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics