Mehak Rohilla
Jan 31, 2018
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International Journal for Research in Applied Science and Engineering Technology
Abstract
: 9, 10- Dihydrolysergic acid has been obtained from lysergol with overall 40% yield. The catalytic reduction of Δ 9,10 double bond in lysergol, protection of hydroxyl group as t-BDMSilyl ether and NH as N-BOC derivative followed by treatment with TBAF gave 1-(t butoxy carbonyl)- 9,10-dihydrolysergol. The oxidation using TEMPO and IDBA in dichloromethane followed by deprotection of N- BOC resulted in 9, 10-dihydrolysergic acid. 1-N-(t-butoxycarbonyl)-9, 10- dihydrolysergic acid (5): To a solution of 1-(t-butoxycarbonyl) – 9, 10- dihydrolysergol (1.16g, 3.25mol) in dichloromethane (20 mL) and water (0.5 mL) was added, TEMPO (0.22 g). The solution was cooled in ice bath and iodobenzene diacetate (5.92 mol) was added in portions. The mixture was stirred at room temperature for 16 hours. The reaction was quenched with the addition of sodium thiosulphate solution (1.82 g in 15 mL water) and organic layer was separated. The aqueous layer was extracted with DCM (10 mL) and the combined DCM layers were washed with water (20 mL), brine (10 mL), dried over sodium sulphate and evaporated to give brown viscous residue. The residue was crystallized in cold methanol to yield 1-N-(tert-butoxy-carbonyl)-ergoline- 8β -carboxylic acid as yellow solid (hygroscopic) (2.42 g, 85%). IR (KBr, cm -1 ): 3318, 2971, 2919, 2676, 2580, 2539, 2489, 2365, 1730, 1715, 1655, 1582, 1439, 1395, 1364, 1345, 1303, 1238, 1249, 1166, 1149, 1131, 1102, 1078, 1056, 1019, 979, 947, 878, 856, 825, 753, 731, 655, 603, 492, 470. 1 H NMR(CDCl 3 , 400 MHz, δppm) : 1.14- 1.29 (m,