Category: 51488-33-6

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鎺?(from H₂O), which, heated 2 h. at 70鎺?in aqueous Triton B, yielded 5-nitro-2-p-tolylpyrimidine (III), m. 217鎺? 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鎺?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鎺?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鎺?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鎺? and refrigerated overnight yielded 1.50 g. IV, pale tan microcrystals, m. 222-3.5鎺? 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鎺?(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鎺? 222-3.5鎺? 79; p-MeC₆H₄, 215-16鎺? 249-50鎺? 87; p-MeOC₆H₄, 216-18鎺? 216-18鎺? 30; p-BrC₆H₄, 261-3鎺? 225-7鎺? 89; p-ClC₆H₄, 240-4鎺? 170-1.5鎺? 81; p-FC₆H₄, 209-11鎺? 154-5鎺? 71; p-O₂NC₆H₄, 294-5鎺? 235-7鎺? 48; p-H₂NO₂SC₆H₄, 207-9鎺? 268-70鎺? 41; p-PhC₆H₄, 245-9鎺? 253-4鎺? 85; m-O₂NC₆H₄, 238-42鎺? 133-4鎺? 79; 3,4-(MeO)₂C₆H₃, 234鎺? 182-3鎺? 67; 3-C₅H₄N, 190-4鎺? 202-3鎺? 36; PhCH₂, 151-3鎺? 170鎺? 77 (picrate, m. 228-30鎺?; 3,4-(MeO)₂C₆H₃CH₂, 153-5鎺? 235鎺? 38; PhCH:CH, 68-70鎺? 219-20鎺? 81; BzCH₂, -, 210-11鎺? 70 (free amidine, m. 185-7鎺?. The following aliphatic amidine HCl salts (alkyl group and m.p. given) did not condense with II: Me, 164-6鎺? Bu, oil (picrate, m. 193-5鎺?; C₁₁H₂₃, 125-7鎺? MeCH(OH), 162-6鎺? HOCH₂CH₂, 81-2鎺? 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鎺? and treated with 2 cc. Ac₂O yielded the 5-AcNH analog of IV, shiny white platelets, m. 208-9鎺?(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鎺? Similarly was obtained 5-amino-2-(p-tolyl)pyrimidine, 95%, m. 183.5-84鎺? 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閳ユ彊閳ユ弲 linkages. In dimethyl ether, the bond angle is 111鎺?and C閳ユ彊 distances are 141 pm. The barrier to rotation about the C閳ユ彊 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

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

Amidines in the Diels-Alder synthesis was written by Martinez, Joaquin Royo. And the article was included in Rev. real. acad. cienc. exact. fís. y nat. Madrid in 1952.SDS of cas: 51488-33-6 This article mentions the following:

Several amidines were prepared as follows. CH₂(OH)CH₂Cl + NaCN → CH₂(OH)CH₂CN (I), b₁₅ 110° (84%); I + finely divided Al (hydroquinone to eliminate polymerization) → CH₂:CHCN (II), b. 77.6-79.0° (69.3%); II + EtOH (distilled from Na), saturated with gaseous HCl → CH₂:CHC(:NH₂Cl)OEt (III), m. 104-4.5° (decomposition), stable in bottles with airtight stoppers; III in absolute EtOH + NH₃ in absolute EtOH (3 hr. agitation, followed by standing 2 days) → CH₂:CHC(:NH₂Cl)NH₂. Similarly, vanillin + NaOH + MeI → (MeO)₂C₆H₃CHO → (MeO)₂C₆H₃CH:NOH → (MeO)₂C₆H₃CN, m. 67°, → (MeO)₂C₆H₃C(:NH₂Cl)OEt, m. 141° (decomposition) → (MeO)₂C₆H₃C(:NH₂Cl)NH₂, m. 237°. Piperonal → oxime, m. 110°, → piperonylonitrile, m. 94.5°, → Et piperonylimidate-HCl, m. 122-3°, → piperonylamidine-HCl, m. 238° (decomposition) → piperonylamidine, m. 167°, → picrate, m. 257°. PhCN → m-O₂NC₆H₄CN, m. 117.5°, → m-O₂NC₆H₄C(:NH₂Cl)OEt → m-O₂NC₆H₄(:NH₂Cl)NH₂, m. 250° (decomposition). There was no reaction comparable to a Diels-Alder, between these amidines and styrene, anethole, or maleic anhydride. MeNO₂ and CH₂(OH)CN, used as solvents, were prepared by the decarboxylation of CH₂(NO₂)CO₂H and by the addition of HCN to CH₂O, resp. In the experiment, the researchers used many compounds, for example, 3,4-Dimethoxybenzimidamide hydrochloride (cas: 51488-33-6SDS of cas: 51488-33-6).

3,4-Dimethoxybenzimidamide hydrochloride (cas: 51488-33-6) belongs to ethers. Ether is less polar than esters, alcohols or amines because of the oxygen atom that is unable to participate in hydrogen bonding due to the presence of bulky alkyl groups on both sides of the oxygen atom. At room temperature, ethers are pleasant-smelling colourless liquids. Relative to alcohols, ethers are generally less dense, are less soluble in water, and have lower boiling points. They are relatively unreactive, and as a result they are useful as solvents for fats, oils, waxes, perfumes, resins, dyes, gums, and hydrocarbons. Vapours of certain ethers are used as insecticides, miticides, and fumigants for soil.SDS of cas: 51488-33-6

Referemce:
Ether – Wikipedia,
Ether | (C2H5)2O – PubChem