Water → 1,2-Dihydro-4-methylnaphthalene

Participants

Reaction Steps

A solution of 101.9 g (0.628 mol) of 1-hydroxy-1-methyl-1,2,3,4-tetrahydronaphthalene and 1.3 g of p-toluenesulphonic acid monohydrate in 1.3 liters of toluene was heated to reflux for 3 h with water being collected by means of a Dean Stark trap. The reaction mixture was cooled, washed with water (3×400 ml), then with saturated sodium chloride solution (400 ml), dried (K2CO3) and evaporated in vacuo to leave 126.4 g of brown liquid. This was vacuum distilled to yield 78.6 g (87%) of the title product as a pale yellow oil, b.p. 59°-62° C./1 mm of Hg. NMR δ(CDCl3) 2.06 (3H, m), 2.26 (2H, m), 2.76 (2H, t), 5.86 (1H, m), 7.11-7.27 (4H, m).

Provenance & Evidence