Diethyl bromomalonate (2) with an equimolar amount of 2-aminophenol (1) in the presence of sodium fluoride undergoes a cyclization reaction to form 2H,4H-2-ethoxycarbonyl-3,4-dihydro-3-oxo-1,4-benzoxazine (3). Furthermore, compound 3 undergoes a condensation reaction with hydrazine hydrate in the presence of methanol to yield 2H,4H-2-hydrazinocarbonyl-3,4-dihydro-3-oxo-1,4-benzoxazine (4), whic...

A gas-liquid chromatographic (GLC) procedure is reported for the quantitation of the trimethylsilyl (TMS) derivatives of substituted 2-hydroxy-2H-1,4-benzoxazin-3(4H)-ones (2-hydroxy-2H-1,4-benzoxazin-3(4H)-one[HBOA]; 2-hydroxy-7-methoxy-2H-1,4-benzoxazin-3(4H)-one[HMBOA];2,4- dihydroxy-2H-1,4-benzoxazin-3(4H)-one[DIBOA]; 2,4-dihydroxy-7-methoxy-2H-1,4-benzoxazin-3(4H)-one[DIMBOA]; and 2,4-dihy...

The effect on mycelial growth of the fungus Botrytis cinerea of a set of structurally related tricyclic hydroquinones [9,10-dihydroxy-4,4-dimethyl-2,3,5,8-tetrahydroantracen-1(4H)-one and 9,10-dihydroxy-4,4-dimethyl-5,8-dihydroanthracen-1(4H)-one derivatives] and tricyclic quinones [4,4-dimethylanthracen-1,9,10(4H)-trione derivatives] was studied. In general, the anthraquinones presented higher...

A gametocidal chromosome, chromosome 2C derived from Aegilops cylindrica, was introduced into six wheat-barley addition lines to establish chromosome-mutationinducing lines. These lines, except the one for chromosome 4H, had a pair of respective barley chromosomes and one 2C chromosome (22”+1’); the line for 4H was doubly monosomic for chromosome 4H and chromosome 2C (21”+2’). In these lines, c...

Nghiên cứu này nhằm đánh giá ảnh hưởng của các phương pháp kích thích khác nhau đến hiệu quả sinh sản ốc bươu đồng. Thí nghiệm được bố trí trong bể có thước (1m × 1m 1 m), mật độ 30 cá thể ốc/m2 (tỷ lệ đực:cái bằng nhau) và mực nước ban đầu là 40 cm. Mỗi thức lặp lại 3 lần với như sau: 1) Tăng 50% nước, kết hợp phơi bóng râm 2 giờ (A50-2h); 2) (A50-3h); 3) 4 (A50-4h); 4) Giảm 75% (D75-2h); 5) (...

Duas novas flavanonas naturais, 5-hidroxi-6,7-(2”,2”-dimetilcromeno)flavanone (1) e 5-metoxi3-hidroxi-6,7-(2”,2”-dimetilcromeno)flavanone (2), foram isoladas dos extratos das raízes de L. yucatanensis e L. xuul, respectivamente. Adicionalmente, quatro novos metabólitos, os flavanóides glicosídicos quercetina-3-ramnoglucosídeo e caempferol-3-ramnoglucosídeo, juntamente com 4hidroxi-N-metil-proli...

Improving the quality of 4H silicon carbide (4H-SiC) epitaxial layers to reduce leakage current 4H-SiC based high-power devices is a long-standing issue in development homoepitaxy. In this work, we compare effect different type dislocations, and discriminate dislocation lines dislocation-related pits on by combining molten-KOH etching tunneling atomic force microscopy (TUNA) measurements. It fo...

The structural, five different elastic constants and electronic properties of 2Hand 4H-Silicon carbide (SiC) are investigated by using density functional theory (DFT). The total energies of primitive cells of 2Hand 4H-SiC phases are close to each other and moreover satisfy the condition E2H >E4H . Thus, the 4H-SiC structure appears to be more stable than the 2Hone. The analysis of elastic prope...

Two novel acrylate monomers, [5-(benzyloxy)-4-oxo-4H-pyran-2-yl]methyl acrylate and {1-[(5-(benzyloxy)-4-oxo-4H-pyran-2-yl)methyl]-1,2,3-triazol-4-yl}methyl acrylate were synthesized by the reaction of 5-benzyloxy-2-(hydroxymethyl)-4H-pyran-4-one and 5-(benzyloxy)-2-{[4-(hydroxymethyl)-1,2,3-triazol-1-yl]methyl}-4H-pyran-4-one with acryloyl chloride in the presence of triethylamine, respectivel...