Studies on Indole Derivatives. VIII. : Synthesis of Thieno [2, 3-b] indole Derivatives and Their Reactions

Synthesis of Thienodolin

“…This procedure gave a total yield of 42% for the synthesis of thienodolin (1a) from the known 6-chloroxindole in three [5] 0 Ϫ 65 [7] steps (Table 1, Scheme 4). The spectroscopic data recorded for 1a are in accordance with the literature data.…”

A Novel Radical Cyclization Approach to Thieno‐Fused Heterocycles

“….57 (dd, J = 3.6, 1.7 Hz, 1 H, HetArH) ppm. 13 C NMR (100 MHz, CDCl 3 , 25°C): δ = 146. 4, 145.6, 145.5, 143.3, 134.8, 130.1, 118.8, 114.8, 112.5, 109.7, 95.8 8, 145.5, 135.5, 129.7, 126.6, 123.6, 119.0, 115.1, 113.8, 109.0, 100.8, 35.4 145.4, 137.0, 133.4, 129.2, 129.0, 125.5, 123.0, 121.2, 119.9, 118.7, 116.5, 110.0, 107.7, 95.8, 33 -2-(3,4,5-trimethoxyphenyl)-8H-thieno[2,3-b]indole-3-carbonitrile (17a): Yield: 73 % (0.69 g); yellow solid; m.p.…”

“…1 H NMR (400 MHz, CDCl 3 , 25°C): δ = 8.08 (d, J = 7.8 Hz, 1 H, ArH), 7.38 (d, J = 6.2 Hz, 2 H, ArH), 7.30-7.26 (m, 1 H, ArH), 7.02 (s, 2 H, ArH), 3.96 (s, 6 H, 2 OMe), 3.91 (s, 3 H, OMe), 3.86 (s, 3 H, NMe) ppm. 13 C NMR (100 MHz, CDCl 3 , 25°C): δ = 153. 6, 145.1, 141.7, 141.0, 138.9, 128.0, 123.4, 122.4, 120.7, 120.4, 119.1, 116.1, 109.3, 104.6, 9 7 .…”

“…8, 141.7, 135.6, 125.7, 123.8, 123.4, 121.3, 120.6, 120.3, 119.2, 115.7, 113.3, 109.3, 108.7, 100.2, 35.1, 32.3 120.7, 120.5, 119.3, 115.3, 109.5, 98.9, 32.4 166.3, 153.2, 140.6, 136.7, 133.4, 130.3, 129.7, 129.5, 129.4, 126.8, 125.3, 117.6, 108.3, 101.1, 19.6 4, 161.7, 145.1, 143.7, 138.7, 131.3, 129.7, 129.3, 129.1, 128.8, 128.4, 126.0, 124.5, 124.2, 118.1, 114.9, 114.2, 90.1, 55.6 8, 145.1, 144.0, 138.8, 134.1, 131.4, 129.6, 129.3, 129.1, 128.9, 128.8, 126.3, 124.4, 117.7, 114.1, 101.0, 90 3 H,ArH),3 H,ArH),2 H,HetArH),6.32 (d,J = 3.4 Hz, 1 H, HetArH) ppm. 13 C NMR (125 MHz, CDCl 3 , 25°C): δ = 150. 0, 146.5, 144.6, 144.2, 143.8, 138.6, 131.1, 129.4, 129.1, 128.9, 128.5, 126.0, 124.0, 118.0, 113.8, 113.1, 111.8, 87.4 2218, 1598, 1502, 1457, 1371, 1183, 1026 cm -1 .…”

“…[11] This methodology or its variants has also been employed for the synthesis of other thieno-fused heterocycles such as thieno [2,3-c]-and thieno[3,2-c]pyrazoles, [12] thieno [2,3-b]indole derivatives, [8,13,14] as well as in total synthesis of thienoindolin alkaloids by Bergman and co-workers. [15] Other preparative methods for aryl/heteroaryl-substituted thienothiophenes utilize palladium-catalyzed cross-coupling or selective metalation reactions [1c,11a-11d,16] including direct C-H arylation of thieno- [2,3-b]thiophenes [17] and intramolecular cyclization of bisacetylene dithioate salts obtained by treatment of metalated bisacetylenes with carbon disulfide.…”