Indole-3-carbonitriles

The substituted furo[3,2-3]indole-2-carbonitrile 228 with a fluorous tin azide (C6F]3CH2CH2)3SnN3) gave the corresponding tetrazole derivative 229 (Equation 4) <1999T8997>. 

Methy 1-5-nltro-3-phenyl indole-2-carbonitrile Hydrogen chloride Boron trifluoride etherate Chromic anhydride... 

Pyrrole and indole carbonitriles are readily prepared by dehydration of oximes. Because the aldehydes are easily available by Vilsmeier-Haack formylation, this represcarboxylic acid derivatives <80CJC409,88SC67l,93JMC10l>. 

A mixture of 1.44 g. (0.0099 mole) of indole-3-carboxaldehyde,2 7.0 g. (0.053 mole) of diammonium hydrogen phosphate, 30 g. (30 ml., 0.34 mole) of 1-nitropropane, and 10 ml. of glacial acetic acid is refluxed for 12.5 hours. During the reflux period the pale-yellow mixture becomes dark red. The volatile reactants and solvent are removed under reduced pressure, and an excess of water is then added to the dark residue. After a short time, crude indole-3-carbonitrile precipitates rapidly. It is separated by filtration and dried under reduced pressure weight 1.20-1.34 g. (85-95%). Crystallization from acetone-hexane, with decoloriza-tion by activated carbon, yields 0.68-0.89 g. (48-63%) of fairly pure indole-3-carbonitrile, m.p. 179.5-182.5° (Note 1). 

Indole-3-carbonitrile has been prepared by the dehydration of indole-3-carboxaldehyde oxime,8 5 indole-3-glyoxalic acid oxime,58 or indole-3-carboxamide 8 by the action of cyanogen... 

Indole, 1-methyl-, 40, 68 Indole-3-carbonttrile, 43, 58 Indoie-3-carboxaldehyde, conversion to indole-3-carbonitrile, 43, 58 Indole-2-carboxylic acid, ethyl ester, 43, 40... 

Litvinov YM, Shestopalov AA, Rodinovskaya LA, Shestopalov AM (2009) New convenient four-component synthesis of 6-amino-2,4-dihydropyrano 2,3-c pyrazol-5-carbonitriles and one-pot synthesis of 6 -aminospiro (3H)-indol-3,4 -pyrano 2,3-c pyrazol -(lH)-2-on-5 -carbonitriles. J Comb Chem 11 914—919... 

A reinvestigation of the experiments on the UV irradiation of l-acetyl-l,2-dihydroquinoline-2-carbonitriles (Reissert compounds) 561 unequivocally demonstrated that the rearrangement via the diradical intermediate 562 gave 4//-3,l-benzoxazines 563 and 565 rather than the benzazete derivatives described earlier. The yields and the type of products were strongly influenced by the substituent R at position 4 while irradiation of the unsubstituted quinoline 561 (R=H) gave 3,1-benzoxazine 563 in nearly quantitative yield, the amount of the corresponding methyl-substituted analog 565 that could be isolated was considerable lower, due to its irreversible isomerization via 562 to the stable cycloprop[/ ]indole derivative 564 (Scheme 107) <199811(49)121 >. 

Phosphorinanones have been utilized as substrates for the preparation of alkenes,11 amines,12 indoles,5,13 and in the synthesis of a series of secondary and tertiary alcohols via reduction,10 and by reaction with Grignard6,11 and Refor-matsky11,14 reagents. Phosphorinanones have also been used as precursors to a series of 1,4-disubstituted phosphorins.15 The use of 4-amino-l,2,5,6-tetrahydro-l-phenylphosphorin-3-carbonitrile for the direct formation of phosphorino-[4,3-d] pyrimidines has been reported.16... 

A series of 4-aryl-6-(l//-indol-3-yl)-2,2-bipyridine-5-carbonitriles 9 was synthesized by Perumal and co-workers [60] via a one-pot MCR of an aromatic aldehyde, a 3-(cyanoacetyl)indole, 2-acetyl pyridine and ammonium acetate by microwave irradiation under solvent-free conditions. The compounds were obtained in high yields and in a very short period of time as compared to conventional heating. Remarkably, when 2,4-dichlorobenzaldehyde was used in this reaction, only the Hantzsch 1,4-dihydropyridine was isolated which had to be separately dehydrogenated to get the targeted pyridine (Scheme 9). 

SYNS 3-ACETYLINDOLE-5-CARBONITRILE INDOLE-5-CARBONITRILE, 3-ACETYI ... 

Figure 2. Formulas of selected D-A compounds which contain 4-dialkylamino group as an electron donor and reveal dual fluorescence behaviour. Top /)-cyano-A,A-dimethylaniline (I, CDMA) and its model derivatives p-cyano-2,A,A-trimethylaniline (II), p-cyano-2,6,A.A-tetramethylaniline (III, CTMA)./)-aminobenzonitrile (IV, ABN) and l-ethyl-2,3-dihydro-indole-5-carbonitrile (V. BIN). Middle 4-(dimethylamino)pyrimidine (VI), 4-(diethylamino)pyrimidine (VTI), 4-(dimethylamino)-5-methylpyrimidine (VIII), 4-(diethylamino)-5-methylpyrimidine (IX) and 4-(dimethylamino)-pyridine (X). Bottom methyl 4-(dimethylamino)benzoate (XI, DMAMB), ethyl 4-(dimethylamino)benzoate (XII, DMAEB), p-(dimethylamino)-benzaldehyde (XIll) and />-(dimethylamino)acetophenone (XIV).

If the 2-position is blocked, cyanation occurs at the 3-position. Similarly, cyanation of 1-methylpyrazole gives a mixture of the 4- and 5-carbonitrile [228]. The efficient substitution observed for many pyrroles, imidazoles [229], and indoles contrasts markedly the addition reactions observed for furans (cf. Chapter 16) and thiophenes [230]. However, this difference may only be apparent. At least for two of the cases already cited [226], it has been demonstrated [231] that the cyanosubstituted pyrroles arise as a result of elimination during workup of the 2,5-addition product originally formed. For benzo[b]thiophenes, cyanation leads predominantly to substitution products [232] ... 

The benzo derivative of pyrrole-2-acetonitrile (299), the indole-2-acetonitrile (305)116 leads in high yield to the orange-red pyrido(l,2-a)indole-9-carbonitriles (308). The requirement of energy for the conversion of (306) to (307) may be smaller than the corresponding gap from (300) to (301). Consequently the thermolysis temperature is found distinctly lowered. 

With (305) the azavinamidinium salt (7u) yields (150—160°, 2 h in quinoline) the pyrimido(3,4-c)indole-4-carbonitrile (309) mp. 160—161°, orange needles (47%), besides a not very soluble, yellow substance, not identified. 

Indole-3-aldehyde, 879 Indole-3-carbonitrile, 745-746 Indole-3-carboxaldehyde, 745-746 Indole-2-carboxylic add, 839 Indoles, 642 Indolines, 642... 

Irradiation of pyridinium perchlorate in dilute perchloric acid (Xirr = 254 nm) is reported to give an amino diol which can be acetylated to the corresponding amido-diacetate (186 R = Ac), and which itself can be converted into the a-mannosidase inhibitor (+)-mannostatin A (187). The photochemical rearrangement of 1-acetyl-l,2-dihydroquinoline-2-carbonitriles to 3,1-benzoxazines and cycloprop[b]indoles has been described, and photo-... 

The checkers obtained pure indole-3-carbonitrile, m.p. 182-184°, by subliming the product at a pressure of 1.5 mm. (bath temperature 165-170°) and recrystallizing the sublimate from a mixture of acetone and light petroleum ether. The recovery was 84%. 

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