Electric Literature of 609-12-1,Some common heterocyclic compound, 609-12-1, name is Ethyl 2-bromo-3-methylbutanoate, molecular formula is C7H13BrO2, 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.
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¡Á15mL). 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-(phenylsulfonyl)butanamide (4a). Yellowish oil, 98% yield. IR (KBr)3590, 3530, 3236, 2970, 2876, 1719, 1450, 1352, 1174, 1085, 865 cm-1; 1H NMR (CDCl3) d 0.93(d, 3H, J 6.3 Hz, CH3), 0.96 (d, 3H, J 6.9 Hz, CH3), 2.21 (octuplet, 1H, CH3CHCH3), 4.10 (d, 1H, J5.7 Hz, CHBr), 7.56 (t, 2H, J 8.1 Hz, CH Ar), 7.67 (t, 1H, J 7.8 Hz, CH Ar), 8.07 (d, 2H, J 7.2 Hz,CH Ar), 8.91 (broad s, 1H, NH); 13C NMR (CDCl3) d 18.8 (CH3), 20.2 (CH3), 32.5 (CH3CHCH3),58.2 (CHBr), 128.5 and 129.0 (CH Ar), 134.3 (CS Ar), 137.7 (CH Ar), 166.0 (CONH); Anal calcdfor C11H14BrNO3S: C 41.26; H 4.41; N 4.37; found C 41.23; H 4.43; N 4.36 %.
The synthetic route of 609-12-1 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;,
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics