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Gromachevskaya, E. V.; Krapivin, G. D.; Kvitkovskii, F. V.; Shein, A. O.; Kul'nevich, V. G.

doi:10.1023/a:1011608722443

Cited by 12 publications

(15 citation statements)

References 7 publications

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“…Analysis of the mass spectra (Tables 4 and 5) for compounds 5a-e and the previously obtained 2-(R-nitrophenyl)-, 2-benzyl-, 2-methyl-, and 4,4-diphenyl-2-vinyl-3,4-dihydroquinazolines (5f-i respectively) [2] shows the presence in all the spectra of peaks from singly-charged molecular ions (M + ), with relative intensities that vary from 92% for dihydroquinazoline 5a to 0.5% for 2-benzyl-4,4-diphenyl-3,4-dihydroquinazoline 5g (Table 4). A characteristic feature of fragmentation of the molecular ions for 3,4-dihydroquinazolines 5a-i is detachment of a phenyl radical from the C (4) atom to form the cation F 1 , which has the maximum intensity in the spectra of compounds 5a,b,e,h,i.…”

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“…Continuing our work on synthesis of 3,4-dihydroquinazolines [2], in this report we describe the reaction…”

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“…Continuing our work on synthesis of 3,4-dihydroquinazolines [2], in this report we describe the reaction of o-aminophenyldiphenylcarbinol (1) with 3-amino-2-cyano-4-methoxymethylene-6-methylthieno[2,3-b]-pyridine (2a), substituted 3-cyanopyridines 2b-c, 3-cyano-2(1H)-pyridones 2d-f, and 3-cyano-2(1H)-pyridinethiones 2g-h.…”

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“…We have shown that in the case of pyridine derivatives, the reaction occurs with formation of 3,4-dihydroquinazolines, which exist in solution in two tautomeric forms. We have determined the general characteristics of initial fragmentation of the indicated products under electron impact.Continuing our work on synthesis of 3,4-dihydroquinazolines [2], in this report we describe the reactionThe reaction of nitriles 1a-h with carbinol 1 was carried out according to the procedure previously developed in [2], in the presence of equimolar amounts of HClO 4 . We established that the direction of the reaction and the product yields are mainly determined by the structure of the nitrile (see Scheme 1).…”

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“…The reaction of nitriles 1a-h with carbinol 1 was carried out according to the procedure previously developed in [2], in the presence of equimolar amounts of HClO 4 . We established that the direction of the reaction and the product yields are mainly determined by the structure of the nitrile (see Scheme 1).…”

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Studies in Quinazoline Chemistry. 3. Synthesis of 2-(2-Pyridon-3-yl)- and 2-[Thieno[2,3-b]pyridin-2(3)-yl]-3,4-dihydroquinazolines

Gromachevskaya

Кайгородова

Фирганг

et al. 2005

Chem Heterocycl Compd

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We have studied the reaction of o-aminophenyldiphenylcarbinol with substituted cyanothienopyridine, cyanopyridines, cyanopyridones, and cyanopyridinethiones. We have shown that in the case of pyridine derivatives, the reaction occurs with formation of 3,4-dihydroquinazolines, which exist in solution in two tautomeric forms. We have determined the general characteristics of initial fragmentation of the indicated products under electron impact.Continuing our work on synthesis of 3,4-dihydroquinazolines [2], in this report we describe the reactionThe reaction of nitriles 1a-h with carbinol 1 was carried out according to the procedure previously developed in [2], in the presence of equimolar amounts of HClO 4 . We established that the direction of the reaction and the product yields are mainly determined by the structure of the nitrile (see Scheme 1).Thus in the case of cyanothienopyridine 2a, cyanopyridines 2b,c, and N-unsubstituted cyano-2-pyridones 2d-e, the corresponding dihydroquinazolinium perchlorates 3a-e are formed; and from N-ethyl-3-cyano-6-methyl-4-methoxymethyl-2-pyridone (2f) and 3-cyano-2-pyridinethiones 2g-h, instead of products of type 3, the 9-phenylacridinium perchlorate (4) is formed according to a competing reaction [3].We have established that in the conversions under consideration, the solvent plays an important role. In nitromethane, we obtain salts 3 in good yields (Table 1). In chloroform, the yields of the latter decrease as a result of a secondary reaction to form the acridinium salt 4. In DMSO, no products of type 3 or 4 are formed. Thus we determined the optimal conditions for synthesis of salts 3: boiling nitromethane as the solvent, equimolar ratios of carbinol 1, nitrile 2, and HClO 4 . Under these conditions, the perchlorates 3a-e were obtained in 50%-85% yields (see Table 1). When treated with an aqueous solution of base, salts 3 are converted to the corresponding free bases 5a-e.

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“…Continuing our work on synthesis of 3,4-dihydroquinazolines [2], in this report we describe the reaction…”

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confidence: 95%

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confidence: 99%

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confidence: 99%

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Studies in Quinazoline Chemistry. 3. Synthesis of 2-(2-Pyridon-3-yl)- and 2-[Thieno[2,3-b]pyridin-2(3)-yl]-3,4-dihydroquinazolines

Gromachevskaya

Кайгородова

Фирганг

et al. 2005

Chem Heterocycl Compd

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ChemInform Abstract: Synthesis of 3,4‐Dihydroquinazolines (IV) in the Reaction of o‐Aminophenyldiphenylcarbinol with Nitriles.

et al. 2002

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Studies on quinazoline chemistry. 4. Unexpected route of acylation of alkyl 2-(4,4-diphenyl-1,2,3,4-tetrahydro-2-quinazolinylidene)acetates. Molecular structure of methyl 2-(4,4-diphenyl)-1,2,3,4-tetrahydro-2-quinazolinylidene)-3-oxobutanoate

Gromachevskaya

Кайгородова

Zavodnik

et al. 2007

Chem Heterocycl Compd

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We have previously reported the reactions of o-aminophenyldiphenylcarbinol with different nitriles and perchloric acid [1,2]. Under the given reaction conditions ethyl cyanoacetate gives ethyl 2-(4,4-diphenyl-1,2,3,4-tetrahydro-2-quinazolinylidene)acetate (1b) which exists as a mixture of Z-and E-isomers [2]. It was also noted that methylation of this compound occurs via N-and C-dimethylation with migration of the exocyclic multiple bond into the heterocycle to form the corresponding ethyl 2-(3-methyl-4,4-diphenyl-3,4-dihydro-2-quinazolinyl)propanoate.In connection with such an unusual alkylation route where, in the presence of two amine nitrogen atoms, alkylation occurs at only one of these and the second alkylation is at the exocyclic multiple bond in α-position to the carboxylate group stimulated us to study the behavior of compounds 1a,b towards an acylation reaction (i.e. in conditions exchanging a "soft" electrophile (R + ) for a hard one (RC + =O)).The reaction was carried out using a twofold excess of the carboxylic acid halide at room temperature in dry benzene [3] (Scheme 1).Elemental analysis, 1 H NMR, and mass spectrometry showed that the products of monoacylation at an exocyclic C=C bond carbon atom 2a-g were obtained in the reaction (Tables 1,2, and 6).The 1 H NMR spectra of compounds 2a-g (Table 2) were recorded in different solvents and showed a marked difference in the number and position of the NH proton signals. Hence in CDCl 3 solution there were four low field signals, each of intensity 0.5H, which points to the presence in solution of two geometric Z-and _______ * For Communication 3 see [1].

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Cited by 12 publications

References 7 publications

Studies in Quinazoline Chemistry. 3. Synthesis of 2-(2-Pyridon-3-yl)- and 2-[Thieno[2,3-b]pyridin-2(3)-yl]-3,4-dihydroquinazolines

Studies in Quinazoline Chemistry. 3. Synthesis of 2-(2-Pyridon-3-yl)- and 2-[Thieno[2,3-b]pyridin-2(3)-yl]-3,4-dihydroquinazolines

ChemInform Abstract: Synthesis of 3,4‐Dihydroquinazolines (IV) in the Reaction of o‐Aminophenyldiphenylcarbinol with Nitriles.

Studies on quinazoline chemistry. 4. Unexpected route of acylation of alkyl 2-(4,4-diphenyl-1,2,3,4-tetrahydro-2-quinazolinylidene)acetates. Molecular structure of methyl 2-(4,4-diphenyl)-1,2,3,4-tetrahydro-2-quinazolinylidene)-3-oxobutanoate

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