Synthesis and reactions of 2,3-diamino-4(3H)-pyrimidinones and 3-amino-2-hydrazino-4(3H)-pyrimidinones. I

A series of new 2,3-diamino-4-pyrimidinones and 3-amino-2-hydrazino-4-pyrimidinones were synthesized by the reactions of β-ketoesters with amino or diaminoguanidines.     

Synthesis of substituted 2-amino-4-quinazolinones via ortho-fluorobenzoyl guanidines

A novel route to 12 substituted 2-amino-4-quinazolinones is described. Starting from 2,6-difluoro-4-methoxybenzonitrile, substitution of one of the fluorine atoms either directly or indirectly with heterocycles (e.g., pyridyl, thiazolyl, pyrazolyl) followed by hydrolysis of the nitrile gave a series of o-fluorobenzoic acid derivatives. Condensation with a set of six N,N-disubstituted guanidines followed by base-promoted ring closure afforded 2-amino-4-quinazolinone derivatives.     

Synthesis of 2-alkoxy-6-aryl-5-cyano-4(3H)-pyrimidinones

The reaction of methyl 3-aryl-2-cyano-3-methoxypropenoates 1 with cyanamide and sodium methoxide in methanol afforded after acid hydrolysis the methyl 3-[(aminocarbonyl)amino]-3-aryl-2-cyanopropenoates 4 . By performing the reaction in higher boiling alcohols the 2-alkoxy-6-aryl-5-cyano-4(3H)-pyrimidinones 2 were obtained in good yields.     

Iodocyclization of 2-allythio-4(3H)-pyrimidinones

It has been established that the iodocyclization of 2-allythio-4-(3H)-pyrimidinones occurs at the N₍₁₎ nitrogen atom with the formation of 3-iodomethyl-7-oxo-2,3-dihydro-8H-thiazolo[3,2-d]pyrimidinium iodides and triiodides.Chelyabinsk State University, Chelyabinsk, 454136. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 211–213, February, 1995. Original articel submitted January 26, 1995.     

Synthesis and properties of novel organosoluble polyimides derived from bis[3-(4-amino-2-trifluoromethylphenoxy) phenyl] ether

A new aromatic ether diamine, bis[3-(4-amino-2-trifluoromethylphenoxy) phenyl] ether, was successfully synthesized via nucleophilic substitution reaction of 3,3′-oxydiphenol and 2-chloro-5-nitrotrifluoromethylbenzene, followed by a catalytic reduction. A series of new polyimides were synthesized from the diamine with various commercially available aromatic dianhydrides via a conventional two-stage process, i.e. ring-opening polyaddition forming the poly(amic acid)s and further thermal or chemical imidization forming polyimides. The resulting polyimides exhibited good solubility in polar solvents, such as N,N-dimethylacetamide, N,N-dimethylformamide, N-methyl-2-pyrrolidinone and common solvents such as chloroform, tetrahydrofuran upon heating and possessed the inherent viscosities of 0.51-0.68 dL/g. The resulting strong and flexible films exhibited excellent thermal stability with the temperature at 10% weight loss is above 502 °C and the glass transition temperature in the range of 191-232 °C. The polyimides also were found to possess high optical transparency.     

Efficient one-pot preparation of 5-substituted-2-amino-1,3,4-oxadiazoles using resin-bound reagents

A robust one-pot solution-phase synthesis of 2-amino-1,3,4-oxadiazoles directly from acylhydrazines and isothiocyanates is described. Commercially-available polymer-supported reagents help facilitate both cyclization and purification. This convenient method benefits from its broad applicability, ease and safety of reagent handling, simple product isolation, and the ability to perform multiple reactions in parallel fashion without need for purification. The details and scope of this reaction strategy are presented herein.     

Synthesis of 3-amino-4-(thienyl-2)furazan

3-Amino-4-(thienyl-2)furazan (3) has been synthesized from 2-acetylthiophene (4) by several routes. Nitrosation of 4, followed by oximation of the resulting oxime salt 5, gave a 6:1 mixture of the E,E and E,Z isomers of thienylglyoxime (1). Estimation of differences and analogies of these isomers' reactivity have been carried out. Oxidation and dehydration of 1 gave furoxan 11 and furazan 2, respectively. Conversion of 2, 12, 13, and 11a, b into the target amine 3 by base-promoted reaction with hydroxylamine has been reported. © 1997 John Wiley & Sons, Inc.     

（2R，4S）-N-叔丁酰基-4-氨基-2-四氢吡咯甲酸甲酯的合成

以(2R,4S)-4-羟基-2-四氢吡咯甲酸为起始原料,经甲酰化,酰化引入叔丁氧羰基,手性反应,甲磺酰化,叠氮化及三苯基膦还原等7步反应合成了(2R,4S)-N-叔丁酰基-4-氨基-2-四氢吡咯甲酸甲酯(总收率29%),其结构经1H NMR和LC-MS表征.     

Synthesis of 6-amino-2-(p-aminophenyl)-4-phenylquinazoline

A study was carried out on the amination of 6-chloro-2-arylquinazolines. The reaction of p-chlorophenyl- and p-nitrophenyl derivatives gives a mixture of mono- and diamination products with predominance of the monoamino products. The desired diamine was also obtained in the reduction of 6-amino-2-(p-nitrophenyl)-quinazoline.Novosibirsk Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences, 630090 Novosibirsk. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 547–550, April, 1995. Original article submitted November 24, 1994. Revision submitted March 10, 1995.     

Synthesis, structure, and magnetic behavior of bis(2-amino-5-fluoropyridinium) tetrachlorocuprate(II)

Reaction of CuCl2 with 2-amino-5-fluoropyridine and HCl in aqueous solution yields bis(2-amino-5-fluoropyridinium) tetrachlorocuprate(II), (5FAP)2CuCl4, (1). The complex crystallizes in the monoclinic space group P21/c with cell dimensions a = 6.926(7) A, b = 21.73(2) A, c = 10.911(10) A, beta = 100.19(2) degrees , V = 1616(3) A3, and R1 = 0.0424 based on 2640 independent reflections. The crystal packing shows that each tetrachlorocuprate ion has four nearest-neighbor Cu(II) ions through three types of Cu-Cl...Cl-Cu potential magnetic interactions: one short Cl...Cl distance (d1 = 3.657 A) and two longer Cl...Cl distances (d2 = 4.073 A) that form a layered distorted honeycomb structure. The third nearest neighbor (d3 = 4.239 A) links these layers into a three-dimensional structure. Both powder and single-crystal magnetic susceptibility measurements on 1, over the temperature range of 1.8-325 K, show significant antiferromagnetic interactions. Attempts to analyze the data using a variety of models showed a best fit to the strong-rung ladder model, with 2Jrung = -17.170(14) and 2Jrail = -5.94(5) K [-11.92(1) and -4.13(3) cm(-1), respectively] for the powder, although a comparable result is obtained using an alternate chain model. However, neither of these two models is compatible with a layered distorted honeycomb crystal packing structure. A first-principles bottom-up theoretical study using the 165 K crystallographic data reproduces the macroscopic properties and reveals that at low temperature the crystal has a 3D magnetic topology (all three magnetic pathways are significant) and a singlet ground state.     

Synthesis of phosphorus-containing polyurethanes from oligoethers prepared from bis(chloromethyl) methylphosphine oxide and glycols

Oligoethers with hydroxyl end-groups were prepared in boiling toluene from bis(chloromethyl)methylphosphine oxide and glycols used as monosodium glycolates. From these oligoethers and diisocyanates (hexamethylenediisocyanate and 2,4-toluene-diisocyanate), phosphorus-containing polyurethanes were synthesized.     

Synthesis of 6-amino-5-cyano-1,4-disubstituted-2(1H)-pyrimidinones via copper-(I)-catalyzed alkyne-azide 'click chemistry' and their reactivity

In this paper we present the room temperature synthesis of a novel serie of 1,4-disubstituted-1,2,3-triazoles 4a-l by employing the (3+2) cycloaddition reaction of pyrimidinones containing alkyne functions with different model azides in the presence of copper sulphate and sodium ascorbate. To obtain the final triazoles, we also synthesized the major precursors 6-amino-5-cyano-1,4-disubstituted-2(1H)-pyrimidinones 3a-r from ethyl 2,2-dicyanovinylcarbamate derivatives 2a-c and various primary aromatic amines containing an alkyne group. The triazoles were prepared in good to very good yields.     

Bis(1-amino-4-azafluoren-9-olium) and bis(2-amino-3-hydroxypyridinium) tetrachlorocobaltates(II): Crystal and molecular structure

Crystal and molecular structure and spectral characteristics are determined for bis(1-amino-4-azafluoren-9-olium) and bis(2-amino-3-hydroxypyridinium) tetrachlorocobaltates(II): CoCl₄(C₁₂H₁₁N₂O)₂ and CoCl₄(C₅H₇N₂O)₂, respectively. The structural units of the complexes are CoCl ₄ ^2? anions and organic cations protonated at the pyridine nitrogen atom.     

Synthesis of 2-amino-4-(2-thienyl)thiazole and its derivatives

The bromination of substituted methyl 2-R-thienyl ketones with bromine in chloroform yielded bromomethyl 2-thienyl ketones. The latter were converted to quaternary pyridinium salts and 2-amino-4-(2-thienyl)thiazoles.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1369–1371, October, 1971.