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. 3543-73-5, name is Ethyl 4-(5-amino-1-methyl-1H-benzo[d]imidazol-2-yl)butanoate, A new synthetic method of this compound is introduced below., SDS of cas: 3543-73-5
[0079] To a solution of 81.3 g (650.6 mmol) 2-bromoethanol, 1 g potassium iodide and 100 g water was added 17.0g (65 mmol) compound (6). The reaction mixture was heated to 65-70 C and held at this temperature for 8 h to 12 h.The pH value of the solution was held between 4.2-5.5 during this period by dropwise addition of a solution of 20.0 g(151.4 mmol) diammonium hydrogen phosphate in 35 g water. The control of pH over the duration of the reaction waseffected through use of a pH electrode. The conversion was followed by HPLC. The reaction was continued until thefraction of compound (7A) was ? 1.5 %. Thereby ca. 8% of compound (7B) had formed and the proportion of compound(7) was ca. 87%. The reaction mixture was subsequently concentrated to dryness at ca. 55-60 C under vacuum. Tothe residue was added 150 g water and, preferably with an alkali metal carbonate, the pH value adjusted to ca. 8.5. Thedesired product (7) was extracted with 200 g methylene chloride or 225 g chloroform, and the organic phase subsequentlywashed with 60 – 80 g water. The organic phase was then concentrated to dryness and the remaining oil or alreadycrystalline residue dissolved in 200 g ethyl acetate or alternatively in 60 g actetonitrile. Compound (7) crystallised at ca.5 C and was filtered under suction, washed with 20 g cold ethyl acetate or alternatively with 15 g cold acetonitrile anddried at 60 -70 C. The yield of compound (7) was 18.3 g (52.4 mmol) with a content of ? 98.2% (80.5 % of theory). Thecrude product contained ?0.6% compound (7A) and compound (7B) respectively as well as 99.2%, wherein compound (7A)was removed below a content of 0.2 % and compound (7B) below 0.3 %. Through the course of the reaction, the contentof compound (7C) was kept below 0.15 %, as this compound can only poorly be removed by recrystallization from theabove described solvents. The overall yield of this step was 76.5% of theory and was thus ca. 12.5% higher than thatdescribed in the procedure using ethylene oxide as according to DD34727 and ca. 31% higher in comparison to thefavoured procedure of W02011079193 involving addition of Huenig?s base.Example 5: Synthesis of ethyl 4-[5-[bis(2-hydroxyethyl)amino]-1-methyl-1H-benzimidazol-
The synthetic route of 3543-73-5 has been constantly updated, and we look forward to future research findings.