Nonbenzenoid aromatic systems. IV. 2-(1-Azulyl)ethyl tosylate buffered acetolysis. Exclusive k.DELTA. process without ion-pair return

Abstract

Ample evidence has recently been reported which demonstrates that two discrete, strongly assisted pathways, ks (solvent assisted) and kA (aryl assisted), compete without crossover in the solvolyses of primary2 and secondary3 ß-arylalkyl arenesulfonates. We wish to report the results of buffered acetolysis of 2-(l-azulyl)ethyl tosylate (la) and certain derivatives which establish it as an exclusive kA process without the complicating factor of ion-pair return. Preliminary results, to be reported later, indicate that this system

Nonbenzenoid aromatic systems. X. Formation, nuclear magnetic resonance spectral identification, and reactions of both Meisenheimer type and methyleneazulenate anions

“…However, amide 15 reacted with 31 by nucleophilic addition to the 4 and 6 positions, the initially formed mixture being thermally equilibrated. Carbonation of lithium 6-dicyclohexylamino-6H-azulenate (20) yields a mixture of azulene mono-(1 and 2), di-(1,2 and 1,3), and tricarboxylic (1,2,3) acids. Carbonation of a mixture of lithium 6-dimethylamino-6H-azulenate and its 4 isomer yields only azulene.…”

Nonbenzenoid aromatic systems. XI. Synthesis and buffered acetolysis of 2-(2-azulyl)ethyl tosylate and nosylate

“…Diethyl 2-Amino-l,3-azulenedicarboxylate (2).8 To 150 ml of absolute ethanol was added 5.00 g (0.217 g-atom) of sodium. After the evolution of hydrogen had ceased, 48.5 g (0.428 mol) of ethyl cyanoacetate was added to form a white suspension.…”

“…Hexanes-dichloromethane (1:1) eluted a broad red-violet band that gave 220 mg (80%) of the title compound, a red-violet oil: ir (neat film) 5.92 (s, C=0) and 9.58 µ (s, C-O); NMR (CC14, internal TMS) 0.80-1.10 (m, C8 ring , 1), 1.77-2.10 (m, C4 ring , 1), 2.23-2.90 (m, Cg.e,? ring H's, 3), 3.00 (s, C3 ring , 1), 5.58 (q, J = 7…”

“…The general Nozoe azulene synthesis was employed for the synthesis of 2-(2-azulyl)ethan-01 (1-OH). 2-Chlorotropone6 was allowed to condense with 2 equiv of ethyl cyanoacetate with ethanolic sodium ethoxide to yield diethyl 2-amino-l,3-azulenedicarboxylate8 (2) in average 70% yield. Diethyl 2-chloro-l,3-azulenedicarboxylate (3) was prepared from 2 by nitrous acid deamination in benzene and hydrogen chloride.9 Sodium ethylcyanoacetate in ethanol effected nucleophilic displacement at C2 of 3, giving diethyl 2-(cyanoethoxycarbonylmethyl) -1,3-azulenedicarboxylate (4) in near-quantitative yield.…”