Synthetic Route of 110661-91-1, In the next few decades, the world population will flourish. As the population grows rapidly and people all over the world use more and more resources, all industries must consider their environmental impact. 110661-91-1, name is tert-Butyl 4-bromobutanoate belongs to esters-buliding-blocks compound, it is a common compound, a new synthetic route is introduced below.
To a solution of ethyl 1-(2-chlorophenyl)-5-(4-chlorophenyl)-4-hydroxy-1H-pyrazole-3-carboxylate (20 g, 53 mmol) in DMF (100 mL) at 0 C. was added KOtBu (7.73 g, 69 mmol). The mixture was stirred at 0 C. for 45 minutes, then tert.-butyl 4-bromobutanoate (15.4 g, 69 mmol) was added at 0 C. The reaction mixture was allowed to warm to room temperature and stir overnight. The mixture was portioned between ether and saturated aqueous NH4Cl. The organic solution was washed with water and saturated aqueous NaCl, dried over Na2SO4, and concentrated in vacuo. The residue was taken into hot cyclohexane. The mixture was allowed to stand for 72 hours. The solvent was decanted and the residue was washed with cold cyclohexane. The solid was then dried under high vacuum to yield 4-(3-tert.-butoxycarbonyl-propoxy)-1-(2-chloro-phenyl)-5-(4-chloro-phenyl)-1H-pyrazole-3-carboxylic acid ethyl ester (I-1a: 20.8 g). 1H NMR (400 MHz, CHLOROFORM-D) ppm 1.4 (s, 9H), 1.4 (t, J=7.1 Hz, 3H), 1.9 (m, 2H), 2.3 (t, J=7.5 Hz, 2H), 4.0 (t, J=5.9 Hz, 2H), 4.4 (q, J=7.1 Hz, 2H), 7.2 (m, 2H), 7.2 (m, 2H), 7.4 (m, 3H), 7.5 (m, 1H); m/z=519.0 (M+1).
The synthetic route of tert-Butyl 4-bromobutanoate has been constantly updated, and we look forward to future research findings.
Reference:
Patent; Pfizer Inc; US2006/241100; (2006); A1;,
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