These common heterocyclic compound, 609-12-1, name is Ethyl 2-bromo-3-methylbutanoate, 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. COA of Formula: C7H13BrO2
General procedure: Benzenesulfonamide (1.2mmol), ethyl alpha-bromophenylacetate or ethyl pheny-lacetate (2.4mmol), and toluene (4mL)werecombinedinasealedtubeequippedwith astirbar.Themixturewasstirredat50Cfor10min,TiCl4 (1.8 mmol) was added, andthereactionmixturewasheatedto115C.Afteravariableperiodoftimethe mixturewasdilutedwithH2O (10mL)toremovetheexcessofTiCl4, filtered,andextracted withAcOEt(3×15mL). The combined organic layers were dried over anhydrous Na2SO4 and thesolventwasevaporatedinvacuo.Crudecompoundswere purified by flash column chromatography (silicagel;cyclohexane=AcOEt 8:2). 2-Bromo-3-methyl-N-[(4-methylphenyl)sulfonyl]butanamide (4b). Orange oil, 57% yield; IR(KBr) 3528, 3235, 2970, 2880, 1718, 1597, 1450, 1171, 1085, 865, 550 cm-1; 1H NMR (CDCl3) d0.94 (d, 3H, J 6.6 Hz, CH3), 0.96 (d, 3H, J 6.6 Hz, CH3), 2.21 (octuplet, 1H, CH3CHCH3), 2.44 (s,3H, CH3Ph), 4.08 (d, 1H, J 6.0 Hz, CHBr), 7.34 (d, 2H, J 8.1 Hz, CH Ar), 7.91 (d, 2H, J 8.1 Hz,CH Ar), 9.01 (broad s, 1H, NH); 13C NMR (CDCl3) d 20.0 and 20.3 (CH3), 21.7 (CH3Ph), 32.4(CH3CHCH3), 58.1 (CHBr), 128.5 and 129.6 (CH Ar), 134.7 (CS Ar), 145.5 (CCH3 Ar), 166.1(CONH); Anal calcd for C12H16BrNO3S: C 43.12; H 4.83; N 4.19; found C 42.99; H 4.81; N 4.18%.
The synthetic route of Ethyl 2-bromo-3-methylbutanoate has been constantly updated, and we look forward to future research findings.
Reference:
Article; Ammazzalorso, Alessandra; Tricca, Maria Luisa; Bruno, Isabella; De Filippis, Barbara; Di Matteo, Mauro; Fantacuzzi, Marialuigia; Giampietro, Letizia; Maccallini, Cristina; Mollica, Adriano; Amoroso, Rosa; Synthetic Communications; vol. 45; 22; (2015); p. 2546 – 2554;,
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