1. M.p. (from ethyl acetate/hexane) 198-199°; ir (potassium bromide): 5.70 μ; nmr (deuteriochloroform): δ 8.12 (d, J = 2.5 Hz, ArH, 1H), 7.4-6.9 (m, Olef. H, ArH, 5H), 2.45 (s, ArCH3, 3H), 2.22 (s, ArCH3, 3H); ms: m/e 362, 364, 366 (indicating 2 Cl).
2. Anal. Calcd. for C18H12O4Cl2: C, 59.53; H, 3.33. Found: C, 59.57; H, 3.48.
3. Dehydrations with Aromatic Sulfonyl Halides in Pyridine.1 A Convenient Method for the Preparation of Esters