Studies on the Syntheses of Isoquinoline Derivatives. II

Synthesis of 7-Methoxy-8-isopropyl-1, 5-dimethyl-3, 4-dihydroisoquinoline

Abstract

There has been no evidence of a hydroisoquinoline compound having iso-propyl radical in its 8-position having been synthesized and this was accomplished by the authors by taking thymol as the starting material. This was led to thymotinaldehyde by the Gattermann's method, methylated with (CH₃)₂SO₄, condensed with acetone and reduced by electrolytic hydrogenation. The oxime of this reduced product was treated with P₂O₅ or POCl₃ in toluene solution to obtain 8-isopropyl-7-methoxy-1, 5-dimethyl-3, 4-dihydroisoquinoline.