Synthesis of Novel 3-Amino-5-trifluoromethylazoles: A Convenient Method of Obtaining N-(Azol-3-yl)amines

Abstract

A convenient method to obtain 10 3-amino-5-trifluoromethyl-5-hydroxy-4,5-dihydroisoxazoles and 18 3-amino-5-trifluoromethyl-1H-pyrazoles by cyclocondensation reaction of 4-amino-4-ethoxy-1,1,1,-trifluorobut-3-en-2-ones [CF 3 COCH=C(OEt)NHR, where R = H, Me, Et, CH 2 CH 2 OH, CMe 2 Et, CH 2 Ph, Ph, 4-NH 2 C 6 H 4 , 4-AcC 6 H 4 , 4-NO 2 C 6 H 4 , 5-methylisoxazol-3-yl, thiazol-2-yl, CH 2 CO 2 Et, CH(Ph)CO 2 Me, CH(i-Bu)CO 2 Et] with hydroxylamine, hydrazine and phenylhydrazine is reported.

Simple Synthesis of 6‐(Trifluoromethyl)‐2,4,5,6‐tetrahydropyrazolo[3,4‐b]pyran Derivatives by One‐Pot, Three‐Component Reactions

“…H 2 SO 4 , by P 2 O 5 or by POCl 3 /Py in toluene as solvent. The result was very similar to those observed in previously reported work [14] where the dehydration reaction was an elimination reaction in which the stability of the activated complex depended on the participation of the electron pair of the neighbouring heteroatom present in the heterocyclic ring. The more difficult dehydration of compounds 4 in relation to α-hydroxy-tetrahydro-pyrindines was a product of the weaker electron-donating strength of the oxygen atom in the pyran ring in relation to the nitrogen atom in the pyrindine.…”

Preparation of novel 5-alkoxy-1,1,1,2,2-pentafluoroalk-4-en-3-ones and their application to a one-pot synthesis of azoles

“…Aromatic pyrazoles similar to 5 were normally produced from the cyclocondensation reactions, however 4,5-dihydro-1-phenylpyrazole intermediates were detected only in some cases. 9,14 The reactions regiospecifically produced the 4,5-dihydroisoxazole derivatives 3, which are derived from exclusive coupling (amino group to olefinic carbon and hydroxyl group to carbonylic carbon) between the enone 2 and hydroxylamine. The pair of doublets (H4) observed in the 1 H NMR spectra centered near 3.1 and 3.4 ppm, with J = 17-20 Hz are typical spectroscopic data for 4,5-dihydro-isoxazoles (3a, 3b).…”

Cu-Catalyzed Synthesis of Novel Benzo[e]pyrazolo[1,5-c][1,3]-thiazine Derivatives

“…1]得到黄色固体 1 [18] . (4a) 11, 120.66, 120.90, 122.06, 124.54, 125.10, 125.71, 126.82, 127.62, 129.36, 129.48, 141.21, 141.62, 142.23 147.65, 155.21;IR (KBr) ν: 3276, 3204, 4105, 3062, 1611, 1601, 1580, 1557, 1513, 1497, 1444, 1353, 1208 92.89, 115.11, 118.05, 120.70, 121.98, 125.12, 125.67, 126.76, 127.74, 129.32, 129.47, 140.64, 141.26, 141.54, 142.303, 155.11, 156.14;IR (KBr) ν: 3207, 2977, 2928, 1611, 1582, 1560, 1531, 1502, 1455, 1443, 1240, 1207, 1047 3296,3208,3118,1599,1582,1557,1515,1505,1446,1353,1206,780,749,692 cm -1 ; 13 C NMR (CDCl 3 , 125 MHz) δ: 21.11, 92.94, 118.15, 120.79, 122.12, 125.18, 125.76, 126.85, 127.76, 129.41, 129.56, 130.05, 134.19, 141.31, 141.65, 142.19, 145.12, 155.20 118.31, 120.80, 122.24, 125.09, 125.87, 127.03, 127.47, 128.41, 129.57, 133.39, 141.21, 155.53;IR (KBr) ν: 3062, 2921, 1612, 1601, 1577, 1559, 1508, 1498, 1455…”