The reaction of an aromatic heterocycle with a proton is called a protonation. One of articles about this theory is 《Benzodiazlnes. VI. Synthesis of 2-substituted-4-hydrazinoquinazolines, 5-substituted [3,4-c]-s-triazolo-, and [1,5-c]tetrazoloquinazolines》. Authors are Postovskii, I. Ya.; Vereschagina, N. N.; Mertsalov, S. L..The article about the compound:2-Aminoquinazolin-4(3H)-onecas:20198-19-0,SMILESS:O=C1NC(N)=NC2=C1C=CC=C2).Reference of 2-Aminoquinazolin-4(3H)-one. Through the article, more information about this compound (cas:20198-19-0) is conveyed.
cf. CA 63, 13256g. 2-R-substituted quinazol-4-ones (I), -4-chloroquinazolines (II), and -4-hydrazinoquinazolines (III) were prepared Treatment of II with CS(NH2)2 gave the corresponding isothiuronium salts, which on treatment with NaOH gave 2-R-substituted-quinazoline-4-thiones (IV). III with HNO2 gave 5-R-substituted[1,5-c]tetrazoloquinazolines (V), with CH(OEt)3 gave 5-R-substituted[3,4-c]-s-triazoloquinazolines (VI). V treated with HCl gave I (a, R = Me) (b, R = Ph) (c, R = α-furyl) (d, R = γ-pyridyl). Thus, 12.5 g. thioisonicotinamide and 12.5 g. anthranilic acid was heated at 150-60° 1 hr. to give 7.5 g. Id, m. 250° (dioxane). IIa-c were prepared according to Scarborough et al. (CA 57, 7263h). IIa m. 86-8° (heptane); IIb m. 124-6° (heptane); IIc m. 122-4° (heptane). A mixture of 7.5 g. Id, 60 cc. POCl3, and 10 g. PCl5 was boiled 4 hrs., POCl3 distilled, the mixture poured onto ice, neutralized with NH3, and filtered, the precipitate washed with H2O and dried, the residue extracted with boiling C6H6, and the extract filtered and evaporated gave 6.5 g., IId, m. 164-6° (heptane). II (0.02 mole) in C6H6 was stirred and cooled, 5-fold excess NH2NH2.H2O in C6H6 added, and the mixture stirred 2 hrs. gave III. II (0.01 mole), 0.01 mole CS(NH2)2, and 50 cc. EtOH boiled 1 hr. and evaporated, the residue dissolved in NaOH, the mixture filtered, and the filtrate acidified with AcOH gave IV. The following III and IV were prepared (R, III m.p., III % yield, IV m.p., and IV % yield given): Me, 180-2° (CHCl3), 80, 217-18° (EtOH), -; Ph, 214-15° (CHCl3), 81, 216-18° (EtOH), 63; α-furyl, 249-50° (dioxane), 76, 219-20° (dioxane), 85; γ-pyridyl, 200-2° (CHCl3,), 97, -, -. Treatment of IIa with NH2NH2.H2O in EtOH gave 50% N,N’-bis(2-methylquinazolyl)-4-hydrazine (VII), m. 280° (isoPrOH). III (0.002 mole) boiled I hr. with 5-fold excess CH(OEt)3 gave VI. NaNO2 (0.002 mole) was added to 0.002 mole III in 2N HCl at 3-5° and the mixture stirred 1 hr. to give V. V were also prepared by treating II with NaN3 in EtOH. The following VI and V were prepared (R, VI m.p., VI % yield, V m.p., and V % yield given): Me, >280°, 50, 163-5°, 60; Ph, 204-6°, 97, 162-3°, 70; α-furyl, 260-2°, 98, 194-6°, 73; γ-pyridyl, 206-7°, 80, 200-2°, 80. Boiling IV with 15-fold excess NH2NH2.H2O in EtOH until no more H2S evolved (8-10 hrs.) gave III. Treatment of V with HCl (1:1) 3 hrs. gave I. The compounds with R = Me differ considerably from the others, both in color and in stability of the intermediate reaction products.
This literature about this compound(20198-19-0)Reference of 2-Aminoquinazolin-4(3H)-onehas given us a lot of inspiration, and I hope that the research on this compound(2-Aminoquinazolin-4(3H)-one) can be further advanced. Maybe we can get more compounds in a similar way.
Reference:
Chiral nitrogen ligands in late transition metal-catalysed asymmetric synthesis—I. Addressing the problem of ligand lability in rhodium-catalysed hydrosilations,
Nitrogen-Containing Ligands for Asymmetric Homogeneous and Heterogeneous Catalysis