2.5. Ionic Liquids Presented in This Review 2020 3. Cyclocondensation Reactions 2020 4. Synthesis of Three-Membered Heterocycles 2022 4.1. Aziridines 2022 5. Synthesis of Five-Membered Heterocycles 2022 5.1. Pyrroles 2022 5.2. Furans 2022 5.3. Thiophenes 2023 5.4. Pyrazoles 2024 5.5. Imidazoles 2025 5.6. Isoxazoles 2027 5.7. Oxazoles, Oxazolines, and Oxazolidinones 2027 5.8. Thiazoles and Thiazolidinones 2028 6. Synthesis of Six-Membered Heterocycles 2030 6.1. Pyridines 2030 6.2. Quinolines 2031 6.3. Acridines 2033 6.4. Pyrans 2033 6.5. Flavones 2035 6.6. Pyrimidines and Pyrimidinones 2035 6.7. Quinazolines 2037 6.8. -Carbolines 2038 6.9. Dioxanes 2039 6.10. Oxazines 2039 6.11. Benzothiazines 2040 6.12. Triazines 2040 7. Synthesis of Seven-Membered Heterocycles: Diazepines 2041

Ionic liquids in heterocyclic synthesis.

Small inorganic rings in the 21st century: from fleeting intermediates to novel isolable entities.

Hypothermic and antipyretic effects of 3-methyl- and 3-phenyl-5-hydroxy-5-trichloromethyl-4,5-dihydro-1H-pyrazole-1-carboxyamides in mice

Thallium(I) supramolecular compounds: Structural and properties consideration

Update 1 of: Ionic liquids in heterocyclic synthesis.

Haloacetylated enol ethers: 12 [18]. Regiospecific synthesis and structural determination of stable 5-hydroxy-1H-pyrazolines

Supramolecular assembling of tectonic [TlI(RC6H4NNNC6H4R)]2 [R = p-NO2] through metal–η2-arene π-interactions and metal⋯O secondary bonding: Synthesis and X-ray characterization of a bis diaryl symmetric-substituted triazenide complex of thallium(I)

The structure of 5-Bromo-4, 6-dimethoxy-4-(trichloromethyl)hexahydro 2-pyrimidinone (3), synthesized from the reaction of 4-methoxy-4-(trichloromethyl)tetrahydro-2-pyrimidinone (2) with bromo and methanol, was determined by nmr spectroscopy, X-ray diffraction, and semiempirical MO calculations. 1H and 13C nmr data shown that only one pair of the diastereoisomers was obtained. The AM1 calculations showed that 3a is the more stable diastereoisomers pair. The x-ray diffraction data confirmed that only the structure 3a (4S5S6R/4R5R6S) of compound 3 was obtained. Compound 3a (C7H10BrCl3N2O3, Mr = 356.43) crystallizes in the orthorhombic space group P212121 with the unit cell dimensions a = 7.112(2), b = 14.719(2) and c = 12.084(3) A, R = 7.32 % and wR2 = 14.92 % for an F 2 refinement on unique data with 2931 reflections collected and 2248 independent (Rint = 4.01%), Flack parameter 0.00(3). #For Part 1, see Ref. 1.

Molecular Structure of Heterocycles: 2 # NMR Spectroscopy, X- ray Diffraction, and Semiempirical MO Calculations of 5-Bromo-4, 6-dimethoxy-4-trichloromethyl-hexahydropyrimidin-2-one.

In the crystal structure of the title compound, C(9)H(7)BrN(4)OS·C(2)H(3)N, the mol-ecules are connected via N-H⋯O and N-H⋯S inter-actions into zigzag chains perpendicular to [001] The mol-ecules in these chains are additionally linked to acetonitrile solvent mol-ecules through N-H⋯N hydrogen bonding The mol-ecules are arranged in layers and are stacked in the direction of the c axis indicative of π-π inter-actions, with distance = 3381 (7) A for the C⋯C interaction parallel to [001] An intra-molecular N-H⋯O hydrogen bond is also observed in the main mol-ecule

Adriano Bof de Oliveira

Papers

Haloacetylated enol ethers: 12 [18]. Regiospecific synthesis and structural determination of stable 5-hydroxy-1H-pyrazolines

Supramolecular assembling of tectonic [TlI(RC6H4NNNC6H4R)]2 [R = p-NO2] through metal–η2-arene π-interactions and metal⋯O secondary bonding: Synthesis and X-ray characterization of a bis diaryl symmetric-substituted triazenide complex of thallium(I)

Molecular Structure of Heterocycles: 2 # NMR Spectroscopy, X- ray Diffraction, and Semiempirical MO Calculations of 5-Bromo-4, 6-dimethoxy-4-trichloromethyl-hexahydropyrimidin-2-one.

1-(5-Bromo-2-oxoindolin-3-yl-idene)thio-semicarbazide acetonitrile monosolvate.

Haloacetylated Enol Ethers. Part 12. Regiospecific Synthesis and Structural Determination of Stable 5-Hydroxy-1H-pyrazolines.