1-(2,3-Dihydro-1,4-benzodioxin-6-yl)ethanone

ALMOST WHITE TO SLIGHTLY BLUE FINE CRYST. NEEDLES

General procedure: Method B: to a solution of compound 4a (1.65 g, 9.94 mmol) inanhydrous CH2Cl2 (100 mL) stirred at 0 C under argon was addedDess-Martin reagent (5.06 g, 11.93 mmol). The mixture was allowedto warm to room temperature after 10 min and stirred for 16 h. Thereaction was quenched with a saturated sodium bicarbonate solution and salts were filtered off. The filtrate was extracted withCH2Cl2. The combined organic layers were dried over MgSO4, filtered and evaporated under reduced pressure. Purification bysilica column chromatography using CH2Cl2 as eluent gave thedesired ketone 5a (1.42 g, 87percent) as a pale yellow solid.General procedure: A 10 mL glass flask equipped with a magnetic stir bar wascharged with a methyl ketone (1 mmol) and dissolved in MeCN (2 mL). To thethermostated solution NH4NO3 (10-25 mol %), I2 (50 mol %) and H2SO4(aqueous 96% solution, 10-20 mol %) were added and the flask was furtherequipped with a balloon filled with air (1 L) and magnetically stirred at 60 C.The consumption of starting material was monitored by TLC. After completionof the reaction, the mixture was cooled to room temperature, diluted withEtOAc (10 mL), and insoluble material identified as ammonium sulfate wasfiltered off. The filtrate neutralized with NaHCO3 (aqueous 10% solution, 2 mL)and Na2S2O3 (aqueous 10% solution, 2 mL) and phase was separated. The waterphase was washed with EtOAc additionally two times (2 5 mL). The combinedorganic phase was dried over anhydrous Na2SO4 and the solvent distilled underreduced pressure. The crude product obtained was analyzed by 1H NMR. Finallythe crude product was purified using column chromatography (SiO2, n-hexane/CH2Cl2 elution) and preparative thin layer chromatography to afford purematerial, which was compared to authentic samples. Detailed data, concerningcatalyst loading, reaction times, yields of pure products and their spectroscopicand other identification data are given in SI in the chapter Characterization dataof isolated final products. Characterization, for example, 1-(9H-fluoren-2-yl)-2-iodoethanone (2i): 1-(9H-Fluoren-2-yl)ethanone (1 mmol, 208.3 mg), NH4NO3(0.15 mmol, 12 mg), I2 (0.50 mmol, 126.7 mg), H2SO4 (aqueous 96% solution, 0.10 mmol, 5.56 lL), 2 mL MeCN, balloon filled with 1 L of air, 60 C, 20 h were used; crystallization from acetone; yield: 187.2 mg (55%) yellow solid, mp 163-164 C. 1H NMR (303 MHz, CDCl3+two drops of DMSO, 25 C, TMS): d (ppm) 3.92 (s, 2H), 4.41 (s, 2H), 7.32-7.44 (m, 2H), 7.54-7.59 (m, 1H), 7.77-7.84 (m, 2H), 7.96-8.02(m, 1H), 8.13 (s, 1H); 13C NMR (76.2MHz, CDCl3+two drops of DMSO, 25 C): d(ppm) 2.3, 36.6, 119.6, 120.7, 125.0, 125.3, 126.9, 128.1, 128.1, 131.5, 139.9, 143.2, 144.3, 146.8, 192.4;MS (ESI):m/z 335 ((M+H)+, 100%);HR-MS (ESI):m/z = 334.9925, calcd for C15H12IO: 334.9933; Anal. calcd for C15H11IO: C, 53.92; H, 3.32; found: C, 54.39; H, 3.05. 3-(2-Iodoacetyl)-2H-chromen-2-one (2o): 3-Acetyl-2H-chromen-2-one (1 mmol, 188.2mg), NH4NO3 (0.20 mmol, 16 mg), I2 (0.50 mmol, 126.7mg), H2SO4 (aqueous 96% solution, 0.1 mmol, 5.56 lL), 2mLMeCN, balloon filledwith 1 Lof air, 60 C, 23 h were used; column chromatography (SiO2, CH2Cl2); yield:182.2mg (58%), yellow solid; mp 135-138 C. 1H NMR (303.0 MHz, CDCl3, 25C, TMS): d (ppm) 4.68 (s, 2H), 7.34-7.46 (m, 2H), 7.64-7.76 (m, 2H), 8.66 (s, 1H); 13CNMR (76.2MHz, CDCl3, 25 C): d (ppm) 6.8, 116.7, 118.1, 121.4, 125.1, 130.2, 134.9, 149.5, 155.3, 158.6, 190.1; MS (ESI): m/z 314.9 ((M+H)+, 100%); HR-MS (ESI): m/z = 314.9523, calcd for C11H8IO3: 314.9518.General procedure: A mixture of acetophenone 4a (120 mg, 1.0 mmol), iodine (254 mg, 1.0 mmol), and CuO (88 mg, 1.1 mmol) in anhydrous methanol (10 mL) was heated at reflux, after disappearance of the reactant (1-12 h, monitored by TLC), 1, 2-diamines 2a (108 mg, 1.0 mmol) and K3PO4*3H2O (266 mg, 1.0 mmol) was added and the mixture was stirred for 12 h at 40 C. The solvent was removed under reduced pressure, and 50 mL water was added to mixture, extracted with EtOAc three times (3×50 mL). The extract was washed with Na2S2O3, dried over anhydrous Na2SO4, and concentrated in vacuo. The residue was purified by column chromatography on silica gel using petroleum ether/EtOAc as the eluent to give the expected products 6aa as pale yellow solid, (80% yield).General procedure: Finely powdered CuO (0.8 g, 10.0 mmol) and I2 (2.53 g, 10.0 mmol) were added to a solution of aryl methyl ketone 9a (1.2 g, 10.0 mmol) in anhydrous MeOH (20 mL). The mixture was refluxed for 1-2.5 h. After disappearance of aryl methyl ketone 9a (monitored by TLC), the mixture was filtered and the solvent was removed under reduced pressure. The residue was poured into 10% Na2S2O3 solution (50 mL), the mixture was extracted with EtOAc (3 × 50 mL), and the organic layer was dried (Na2SO4). Removal of the solvent and purification of the residue by column chromatography gave the desired product 1a in 96% yield.

Molecular Weight:178.18
XLogP3:0.5
Hydrogen Bond Acceptor Count:3
Rotatable Bond Count:1
Exact Mass:178.062994177
Monoisotopic Mass:178.062994177
Topological Polar Surface Area:35.5
Heavy Atom Count:13
Complexity:202
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes