Diethyl Ether → potassium thioethoxide DMF

Participants

Reaction Conditions

Reaction Steps

trans-Δ7 -6α-Hydroxy-4α,β-(3'-hydroxyphenyl)-2-methyloctahydroisoquinoline (6). A solution of potassium thioethoxide/DMF was prepared as follows. To DMF (30 mL degassed by freeze/thaw) was added potassium tert-butoxide (1.5 g, 13.4 mmol), and the suspension was degassed and flushed thoroughly with argon. Ethanethiol (1.22 mL, 1.64 mmol) was added and the butoxide dissolved leaving a clear, colorless solution. Ether 7 (40 mg, 0.15 mmol) in DMF (1 mL) was thoroughly degassed and placed under argon. The thioethoxide solution (1 mL, 0.44 mmol) was added, and the solution was heated at 150° C. for 10 h, cooled, poured into H2O (20 mL), the pH adjusted to 14, and extracted with CHCl3 (3×4 mL) after which the pH was lowered to 8 and the solution was extracted with 9/1 CHCl3 /2-propanol (4×4 mL). The combined organic phases were washed with saturated NaCl (10 mL), dried, and evaporated to a mixture of phenols (33 mg). Trituration of the residue with hot benzene and cooling returned 24 mg (60%) of pure 6 as an amorphous solid: NMR δ7.3-6.5 (m, 4H), 5.84 (distorted dd,J=10 Hz, 2H), 4.07 (m, 1H), 2.29 (s, 3H); IR 3550, 3247 (b), 1582 cm-1 ; mass spectrum m/e (rel intensity) 259 (100), 258 (32), 188 (91), 71 (94), 70 (59). Sublimation gave mp 199°-203° C. Anal. Calcd for C16H21NO2 : C, 74.1; H, 8.2; N, 5.4. Found: C, 73.8; H, 8.1; N, 5.4.

Provenance & Evidence