4‐Methyl‐1‐phenyl‐2,3‐dihydro‐1 H ‐Phosphole 1‐Oxide

image [707‐61‐9] C 11 H 13 OP (MW 192.20) InChI = 1S/C11H13OP/c1‐10‐7‐8‐13(12,9‐10)11‐5‐3‐2‐4‐6‐11/h2‐6,9H,7‐8H2,1H3 InChIKey = YMKWWHFRGALXLE‐UHFFFAOYSA‐N (catalyst for P 3 /P 5 redox processes and P 5 /P 5 processes) Alternative Name: 3‐methyl‐1‐phenyl‐2‐phospholene 1‐oxide. Physical Data: colorless viscous liquid (bp = 173–174 °C/0.7 mm, 156–157 °C/0.7 mbar) that solidifies to a white solid (mp = 60–65 °C). Solubility: CH 2 Cl 2 , CHCl 3 , toluene, and most organic solvents. Form Supplied in: colorless liquid with crystals; widely commercially available with >95% purity. Analysis of Reagent Purity: 31 P NMR (CDCl 3 ) δ 20.6 ppm and 1 H NMR (CDCl 3 ) δ 7.85‐7.35 (m, 5 H ), 5.88 (d, 1 H , J H‐P = 25.1 Hz), 2.80–2.15 (m, 4 H ), 2.05 (s, 3 H ) ppm. Preparative Methods: can be synthesized using the McCormack synthesis. 1,2 Starting from isoprene and dichlorophenylphosphine, the formation of 1,1‐dichloro‐4‐methyl‐1‐phenyl‐2,3‐dihydro‐1 H ‐phosphole was observed. After hydrolysis of this intermediate, the crude desired compound was obtained. The synthesis by isomerization of 3‐phospholene oxide is also possible. 3 Purification: fractional distillation. A small amount of impurities could remain (which is most probably a linear copolymer). Handling, Storage, and Precautions: hygroscopic, stable over 300 °C. Handle with gloves under the fume hood.