First example of a synthesis of the tetracyclic 2,4-di(tert-butyl)- 6,7-dihydrofuro[2',3':3,4]cyclohepta- [1,2-b]indole system

Synthesis of tetracyclic system of 2,4‐di(tert‐butyl)‐6,7‐dihydrofuro[2′,3′:3,4]cyclohepta[1,2‐b]indole

“…Synthesis of 5,5-dimethyl-1-[2-(4,4-dimethylpentan-3-on-1-yl)-1H-indol-3-yl]hexane-1,4-dione (16). A total of 35% hydrochloric acid (7 mL) was added to the cooled solution (10)(11)(12) C) of compound 12a (1.0 g, 2.2 mmol) in AcOH (25 mL). The reaction mixture was kept at 45 C for 9 h. After completion of the reaction (TLC monitoring), the mixture was poured into water, neutralized with NaHCO 3 , and extracted with CH 2 Cl 2 (3 Â 50 mL).…”

“…In continuation of our study of [2-(benzoylamino)-phenyl]bis(5-tert-butyl-2-furyl)methanes recyclization, we have found that their treatment with POCl 3 in benzene in the presence of one drop of water yields earlier unknown furo[2 0 ,3 0 :3,4]cyclohepta[1,2-b]indoles [11]. Herein, we describe the full results of this investigation.…”

2,5-Dimethyl-7,8,9,10-tetrahydrocyclohepta[b]indol-6(5H)-one

“…For the importance of the indole nucleus, see: Satoshi & Tominari (2001). For the synthesis of fused cyclohept [b]indole derivatives, see: Butin et al (2010); Fujimori & Yamane (1978); Wahlströ m et al (2007). For heteroannulated cyclohept [b]indole derivatives, see: Kavitha & Prasad (1999.…”

“…Since the indole nucleus is present in a large number of naturally occurring as well as biologically active molecules, indole derivatives are of considerable contemporary interest and importance (Satoshi & Tominari, 2001). Due to the importance of these compounds, several fused cyclohept[b]indole derivatives have been synthesized (Butin et al, 2010);Fujimori & Yamane, 1978); Wahlström et al, 2007)). In our laboratory 7,8,9,10-tetrahydrocyclohepta[b]indol-6(5H)-one was used as a synthon to derive various heteroannulated cyclohept[b]indole derivatives (Kavitha & Prasad 1999).…”