Synthesis
Add 332.3g of -pentolactone and 2.33L of benzene into a 5L three-necked flask equipped with a thermometer, mechanical stirring, reflux tube and exhaust gas receiving device, turn on the stirring, add 1.77kg of anhydrous aluminum trichloride in batches at room temperature, and control the addition of 2h, heat the reaction system until the reflux reaction temperature was controlled at 80, the reaction time was controlled at 14h, and the reaction of -pentolactone was detected to be complete by TLC. The reaction time was controlled at 14h, and the reaction of -pentolactone was detected by TLC, the reaction was stopped, cooled to room temperature, and the reaction system was slowly poured into a mixture of 8kg crushed ice and 1.4L concentrated hydrochloric acid, stirred, and partitioned. The aqueous phase was extracted with 2L of toluene once; the organic phase was combined, and the organic phase was washed sequentially with 10% NaOH solution and 1L of water, dried with methanamine powder, filtered, concentrated under reduced pressure to remove the organic solvent, and then distilled under reduced pressure, and the fractions were collected at 178-182 to obtain the crude product of 456.4g, and the secondary distillation (20cm Wechsler fractional distillation column) yielded 1-benzo[b]cycloheptanone of 378.6g, with the yield of 71.2%. 71.2%, purity was 98.9%.
Purification Methods
Purify it by dissolving in toluene, washing with aqueous 5% NaOH, then brine, drying (MgSO4), and distilling. The 2,4-dinitrophenylhydrazone has m 210.5o, 207-208o (from CHCl3/MeOH). The Z-O-Picryloxime has m 156-157o (from Me2CO/MeOH), the E-O-picryloxime has m 107o. The oxime has m 106.5-107.5o. [UV: Gilmore & Horton J Am Chem Soc 73 1411 1951, Hedden & Brown J Am Chem Soc 75 3744 1953, Huisgen et al. Chem Ber 90 1844 1957, Beilstein 7 IV 1029.]
