2-Substituted-5-nitropyrimidines by the condensation of sodium nitromalonaldehyde with amidines was written by Fanta, Paul E.;Hedman, Edward A.. And the article was included in Journal of the American Chemical Society in 1956.Application of 51488-33-6 This article mentions the following:
p-MeC6H4C(:NH)NH2 (I) (1.86 g.) and 1.57 g. Na[C(NO2)(CHO)2] (II) mixed in 25 cc. H2O at room temperature gave I-II salt, fine white needles, m. 148-50° (from H2O), which, heated 2 h. at 70° in aqueous Triton B, yielded 5-nitro-2-p-tolylpyrimidine (III), m. 217°. PhC(:NH)NH2.HCl (IIIa) and II mixed in H2O at room temperature darkened and resinified on standing and the product was characterized only by conversion to 5-nitro-2-phenylpyrimidine (IV) on heating in aqueous Triton B. IIIa.2H2O and II.H2O heated 4 h. with aqueous Triton B at 70° gave 79% IV; IIIa and II heated similarly with aqueous K2CO3 gave 66% IV and with aqueous NaOH 42% IV (NH3 evolved during the reaction); II and IIIa refluxed 4 h. with aqueous NaOH gave no IV but NH3 was evolved during the reaction and BzOH was isolated from the mixture II and IIIa heated 15 min. at 80° with Ac2O-pyridine yielded 85% IV; a similar run but without the pyridine gave only 40% IV. II and IIIa refluxed 2 h. with EtOH and NaOEt, or kept 12 h. at 0° with alc. HCl gave no IV. IIIa.2H2O.HCl (1.94 g.) and 1.57 g. II in 25 cc. H2O treated with 1 cc. Triton B, heated 4 h. at 65-70°, and refrigerated overnight yielded 1.50 g. IV, pale tan microcrystals, m. 222-3.5°. II (2.8 g.) mixed intimately with 1.8 g. MeC(:NH)NH2.HCl, treated with a few drops piperidine, heated 1 h. on the steam bath, treated with 1 g. Na2CO3, heated 0.5 h., dissolved in a small amount of H2O, the solution cooled, filtered, and the residue extracted with ligroine gave less than 1% 2-methyl-5-nitropyrimidine, m. 186-7° (from ligroine); a similar run with NaOH in EtOH gave no better yields. II treated with concentrated NH4OH or with NH4Cl, NH4OAc, or AcNH2 in the presence of Triton B gave an intractable resin. The appropriate nitrile (0.5 mol) and 0.5 mol absolute MeOH treated with a slight excess of dry HCl in 25 cc. absolute Et2O, and the resulting solid imidic ester HCl salt decomposed with 10% NH3 in absolute MeOH gave the corresponding amidines which were isolated as their HCl salts and converted by the method described for the preparation of III to the corresponding 2-substituted-5-nitropyrimidines (V); in this manner were prepared the following arylamidine HCl salts and V (aryl group of amidine = 2-substituent of V, m.p. of amidine HCl salt, m.p. and % yield of V given): Ph, 70-3°, 222-3.5°, 79; p-MeC6H4, 215-16°, 249-50°, 87; p-MeOC6H4, 216-18°, 216-18°, 30; p-BrC6H4, 261-3°, 225-7°, 89; p-ClC6H4, 240-4°, 170-1.5°, 81; p-FC6H4, 209-11°, 154-5°, 71; p-O2NC6H4, 294-5°, 235-7°, 48; p-H2NO2SC6H4, 207-9°, 268-70°, 41; p-PhC6H4, 245-9°, 253-4°, 85; m-O2NC6H4, 238-42°, 133-4°, 79; 3,4-(MeO)2C6H3, 234°, 182-3°, 67; 3-C5H4N, 190-4°, 202-3°, 36; PhCH2, 151-3°, 170°, 77 (picrate, m. 228-30°); 3,4-(MeO)2C6H3CH2, 153-5°, 235°, 38; PhCH:CH, 68-70°, 219-20°, 81; BzCH2, -, 210-11°, 70 (free amidine, m. 185-7°). The following aliphatic amidine HCl salts (alkyl group and m.p. given) did not condense with II: Me, 164-6°; Bu, oil (picrate, m. 193-5°); C11H23, 125-7°; MeCH(OH), 162-6°; HOCH2CH2, 81-2°. IV (0.20 g.) in 0.40 g. NaOH in 10 cc. H2O treated with warming and stirring with 1.05 g. Na2S2O4, centrifuged to remove a small amount of brown solid, cooled to 5°, and treated with 2 cc. Ac2O yielded the 5-AcNH analog of IV, shiny white platelets, m. 208-9° (from 20% aqueous EtOH). IV (2.00 g.) in 200 cc. absolute EtOH hydrogenated 0.5 h. at room temperature and 3 atm. pressure over 0.6 g. 5% Pd-C, the suspension evaporated to dryness in vacuo on the steam bath, the residue extracted with boiling C6H6, and the extract cooled yielded 1.50 g. 5-amino-2-phenylpyrimidine (VI), m. 90.5-92°. Similarly was obtained 5-amino-2-(p-tolyl)pyrimidine, 95%, m. 183.5-84°. VI diazotized under various conditions and each reaction mixture tested for the presence of aromatic diazonium salt with an alk. solution of 2-C10H7OH in no case gave a color. In the experiment, the researchers used many compounds, for example, 3,4-Dimethoxybenzimidamide hydrochloride (cas: 51488-33-6Application of 51488-33-6).
3,4-Dimethoxybenzimidamide hydrochloride (cas: 51488-33-6) belongs to ethers. Ethers are good solvents partly because they are not very reactive. Most ethers can be cleaved, however, by hydrobromic acid (HBr) to give alkyl bromides or by hydroiodic acid (HI) to give alkyl iodides. Ethers feature bent C–O–C linkages. In dimethyl ether, the bond angle is 111° and C–O distances are 141 pm. The barrier to rotation about the C–O bonds is low. The bonding of oxygen in ethers, alcohols, and water is similar. In the language of valence bond theory, the hybridization at oxygen is sp3.Application of 51488-33-6
Referemce:
Ether – Wikipedia,
Ether | (C2H5)2O – PubChem