and dried over anhydrous mtlgnesium sulfate. The drying agent was removed by filtration, and the solvent was evaporated to give 10.50 g (84% yield) of 61 as a light yellow oil: ir (neat) 3380 (enamine NH), 3050-2850 (CH), 1735 (ester C=O), 1670 (C==N), and 1615 (C==C) cm-l; pmr (CCI,) 2.80-3.50 (4 H, m, aromatic protons), 5.85 (2 H, q, C02CH2CH3), 7.4C-8.60 (7 H, m, cyclohexyl protons), 8.35 ( 3 H, s, SCH3), and 8.75 (3 H, t, COZCHZCH~).
l-Carbethoxy-1,2,3,4-tetrahydrocarbazole (57). A solution of 10.00 g (0.035 mol) of 61 in 200 ml of absolute ethanol was stirred with 15 teaspoonsful of W-2 Raney nickel at room temperature for 6 hr. The catalyst was removed by filtration and washed thoroughly with ethanol (care should be taken to keep the catalyst moist with solvent since the dry catalyst is highly pyrophoric).
The combined ethanol solutions were evaporated in Gacuo to give an oil which was chromatographed on silica gel (elution with methylene chloride) to give 7.30 g (88%) of 57, bp 125-130" (0.2 mm) [lit.z* bp 125-135" (0.15 mm)]; ir (neat) 340C (indole NH) and 1730 cm-' (ester -0); nmr (CCL), T 1.73 (1 H, br s, NH, exchanges with deuterium oxide), 2.70-3.20 (4 H, m, aromatic protons), 5.90 (2 H, q, COZCHSCH~), 6.30 (1 H, m, CHCO*Et), 7.35 (2 H, m, C-4 protons), 7.70-8.50 (4 H. m, C-2 and C-3 protons), and Acknowledgment.