A New and Efficient Synthesis of 2H-3, 1-Benzoxazine Compounds

2H-3, 1-Benzoxazine derivatives were synthesized by cyclocondensation of 5-nitro-2- cyanoaniline with relative ketone or aldehyde with ZnCl2 as a catalyst. This is a new efficient synthetic route of 2H-3, 1-benzoxazine cyclic compounds.

Synthesis, Crystal Structure and Antitumor Activity of 4-(tert-butyl)-5-(1H-1,2,4-triazol-1-yl)-N-(2-hydroxy-3,5-diiodinebenzyl)-thiazol-2-amine

The title compound, 4-（tert-butyl）-5-（1 H- 1,2,4-triazol- 1 -yl）-N-（2-hydroxy-3,5-diio- dinebenzyl）thiazol-2-amine, was synthesized via the reduction of 4-（tert-butyl）-5-（1H-l,2,4- triazol-l-yl）-N-benzylidene-thiazol-2-amine with NaBH4, and its crystal structure was determined by single-crystal X-ray diffraction. The compound crystallizes in monoclinic system, space group P21/c with a = 7.91944（19）, b = 10.5250（3）, c = 24.4985（6） A, Z = 4, V = 2041.66（9） A3, Mr = 599.22, Dc = 1,949 Mg/m3, S = 1.120, p = 3.203 mm-1, F（000） = 1152, the final R = 0.0283 and wR = 0.0592 for 3490 observed reflections （I 〉 2σ（I））. X-ray analysis displays that the crystal water takes part in three intermolecular hydrogen bonds of O（2）-H（2A）…O（1）, O（2）-H（2B）…N（I） and N（5）-H（5）…O（2）, and an octatomic ring R^（8） is formed via intramolecular hydrogen bond of O（I）-H（IA）…N（4）. Furthermore, the I…I contacts are involved in stabilizing the overall three-dimensional network structure. The preliminary biological test shows the title compound has good antitumor activity with the IC50 value of 26 μM against the Hela cell line.

Synthesis, Crystal Structure and Antitumor Activity of (E)-1-(7-Methoxy-2,2-dimethyl-2,3-dihydrobenzofuran-5- yl)-3-(2-methoxyphenyl)-2-(1H-1,2,4-triazol-1-yl)propenol

The title compound, （E）-1-（7-methoxy-2,2-dimethyl-2,3-dihydrobenzofuran-5-yl）- 3-（2-methoxyphenyl）-2-（1H-1,2,4-triazol-1-yl）propenol （3a）, was synthesized by the Aldol con- densation reaction of 1-（7-methoxy-2,2-dimethyl-2,3-dihydrobenzofuran-5-yl）-2-（1,2,4-triazol- 1-yl）ethanone with 2-methoxybenzaldehyde and then reduced with NaBH4, and its crystal structure was determined by single-crystal X-ray diffraction： monoclinic system, space group P21 with a = 6.2002（3）, b = 12.8452（7）, c = 13.2257（7） ？, Z = 2, V = 1031.23（9） ？3, Mr = 407.46, Dc = 1.312 Mg/m3, S = 1.054, μ = 0.091 mm-1, F（000） = 432, the final R = 0.0353 and wR = 0.0769 for 3161 observed reflections （I 〉 2σ（I））. X-ray analysis displays that the title compound adopts an E configuration for the C（7）=C（8） double bond and S configuration for the chirality center with the specific rotation of –63.75°. Furthermore, the stability of the crystal was maintained through the intermolecular hydrogen bond O（1）–H？？？N（3）. The antitumor assay exhibits that the title compound 3a （E configuration） has a good antitumor activity against the Hela cell line with the IC50 value of 36.9 μM, which is better than that of 3b （Z configuration）.

Synthesis, Crystal Structure and Fungicidal Activity of (Z)-3,3-Dimethyl-1-(1H-1,2,4-triazol-1-yl)butan-2-one O-2-Chlorobenzyl Oxime Nitrate

The title compound has been synthesized by the reaction of 3,3-dimethyl-1-（1H-1,2,4-triazol-1-yl）butan-2-one oxime with 2-chlorobenzyl chloride, and then treated with 65～68% HNO3. Its crystal structure was determined by single-crystal X-ray diffraction. The crystal belongs to the monoclinic system, space group P21/c with a = 14.5481（8）, b = 9.3351（5）, c = 13.1911（7） , β = 98.9450（10）°, Z = 4, V = 1769.67（17） 3, Mr = 369.81, Dc = 1.388 g/cm3, S = 1.06, μ = 0.247 mm-1, F（000） = 776, the final R = 0.0352 and wR = 0.0960 for 3069 observed reflections （I 2σ（I））. X-ray crystal structure presents the intramolecular N–H…O hydrogen bond. The packing is nearly parallel without π-π stacking interactions between two adjacent phenyl rings and stabilized by Van der Waals force. The preliminary bioassay shows that the title compound possesses fungicidal activity against Gibberella zeae at the dosage of 25 mg/L.

Ultrasound-assisted synthesis and preliminary bioactivity of novel 2H-1,2,4-thiadiazolo[2,3-a]pyrimidine derivatives containing fluorine

Eight novel 5,7-disubstituted-2-{5-methyl-3-（4-trifluoromethylphenyl）isoxazol-4-ylcarbonylimino}-2H-1,2,4-thiadiazolo[2,3- a]pyrimidines were synthesized by multi-step reactions in yields 68-85%.Reactions were carried out either by ultrasound irradiation or conventional method,and found it was faster and more efficient under ultrasonic irradiation.Preliminary herbicidal activities against Echinochloa crus-galli,Digitaria sanguinalis and Chenopodium serotinum were also evaluated by flat-utensil method,and the results indicated that the target compounds exhibited significant activities,some were even higher than the control herbicide.

Improved microwave-assisted catalyst-free synthesis of9-aryl-5,9-dihydropyrimido[4,5-d][1,2,4]triazolo[1,5-a]pyrimidine-6,8(4H,7H)-dione derivatives

Agreen regioselective synthesis of some new and known 9-aryl-5,9-dihydropyrimido[4,5-d][l,2,4]triazolo[1,5-a]pyrimidine-6,8（4H,7H）-diones has been described via the microwave-assisted one-pot reaction of 3-amino-1H-1,2,4-triazoles,aromatic aldehydes and barbituric acids under solvent- and catalyst-free conditions.This operationally simple procedure is less laborious and provides a better scope than previously reported procedures.