Application of 37746-78-4, These common heterocyclic compound, 37746-78-4, name is (E)-Ethyl 4-bromobut-2-enoate, 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.
General procedure: A solution of TMSCl (3 mol%) in anhyd 1,4-dioxane (1 mL) wasadded to a suspension of Zn dust (2 equiv) in anhyd 1,4-dioxane(3 mL), and the resulting suspension was refluxed with vigorousstirring for 25 min. The appropriate nitrile (2 mmol) in dry 1,4-dioxane (1 mL) and ethyl (E)-4-bromobut-2-enoate (12; 2equiv) in dry 1,4-dioxane (1 mL) were simultaneously addeddropwise to the refluxing suspension during 10 min by usingtwo syringes. The resulting light-green mixture was refluxeduntil all the starting material was consumed and the colorchanged to brown (TLC; 3-6 h). The mixture was cooled to r.t.then centrifuged (700 rpm). The upper solution was decantedand the remaining solid was washed with 1,4-dioxane (4 ¡Á 1mL). The 1,4-dioxane solutions were combined and concentratedto about 1 mL under reduced pressure in a rotatory evaporator.The residue was treated with 50% aq K2CO3 until the pHreached 13 (~5 mL). The resulting mixture was stirred for 30min at r.t. (30 C) then diluted with CH2Cl2 (10 mL) and H2O (10mL). The organic layer was separated, washed sequentially withH2O (2 ¡Á 10 mL) and brine (10 mL), dried (Na2SO4), and evaporatedunder reduced pressure to give a crude product that waspurified by column chromatography [silica gel (100-200 mesh);15-60% EtOAc-hexane].6-Phenylpyridin-2(1H)-one (13a)By following the general procedure, the reaction of PhCN (5a;201 mg, 1.94 mmol) with crotonate 12 (374 mg, 1.94 mmol) inthe presence of Zn (252 mg, 3.88 mmol) and TMSCl (7 mg, 3 mol%) in 1,4-dioxane (6 mL) for 4 h, followed by hydrolysis with 50%aq K2CO3 (5 mL) gave a light-yellow solid; yield: 205 mg (62%);mp 194-195 C; Rf = 0.5 (hexanes-EtOAc, 2:1).IR (KBr): 2904, 1643, 1612, 1550, 1493, 990, 921, 795, 761 cm-1.1H NMR (400 MHz, CDCl3): delta = 12.49 (br s, 1 H), 7.72 (d, J = 6.9Hz, 2 H), 7.59-7.40 (m, 4 H), 6.55-6.47 (m, 2 H). 13C NMR (100MHz, CDCl3): delta = 165.4, 147.1, 141.5, 133.6, 130.1, 129.2, 126.8,118.7, 105.0. HRMS (ESI): m/z [M + H] calcd for C11H9NO:172.0762; found: 172.0750.
The synthetic route of 37746-78-4 has been constantly updated, and we look forward to future research findings.
Reference:
Article; Rao, H. Surya Prakash; Muthanna, Nandurka; Padder, Ashiq Hussain; Synlett; vol. 29; 12; (2018); p. 1649 – 1653;,
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