Sodium Hydroxide → HCID 19095290, compound

Participants

Reaction Conditions

Reaction Steps

N-[2-(4,5-Dihydro-5-methyl-1H-benzo[g]indol-1-yl)ethyl]acetamide (5.0 g) was treated with 20 ml of phosphorus oxychloride under argon and the mixture was stirred at 100° C. for 30 minutes. The cooled mixture was added to 2000 ml of ice-water and treated with 200 ml of 28% sodium hydroxide solution. The mixture was extracted once with 300 ml of methylene chloride and twice with 100 ml of methylene chloride each time, the organic phases were combined, dried with MgSO4 and freed from solvent. 4.6 g of residue were chromatographed on 200 g of silica gel with methylene chloride/methanol mixtures (49:1 to 9:1) as the eluent. Of the crude product, 3.9 g of brown oil, 1.9 g were dissolved in a 20-fold amount of ethanol and treated with 1.1 equivalents of a saturated solution of fumaric acid in ethanol. After concentration to 10 ml and addition of 10 ml of ethanol and 70 ml of ethyl acetate there separated ochre-yellow crystals which were recrystallized from an ethanol/ethyl acetate mixture (1:2, 30-fold amount). There were obtained 1.7 g (43%) of 5,6,10,11-tetrahydro-5,8-dimethylbenzo[g]pyrazino[1,2-a]indole fumarate (2:3); m.pt.: 156°-157° C. (dec.).

Provenance & Evidence