- Alkali and alkaline earth metal salts of tetrazolone: Structurally interesting and excellently thermostable
-
Tetrazolone (5-oxotetrazole) was synthesized by a moderate strategy through three steps (addition, cyclization and catalytic hydrogenation) avoiding the unstable intermediate diazonium, as reported during the previous preparation. Alkali and alkaline earth metal salts with lithium (1), sodium (2), potassium (3), rubidium (4) caesium (5), magnesium (6), calcium (7), strontium (8) and barium (9) were prepared and fully characterized using elemental analysis, IR and NMR spectroscopy, DSC and TG analysis. All metal salts were characterized via single-crystal X-ray diffraction. They crystallize in common space groups with high densities ranging from 1.479 (1) to 3.060 g cm-3 (5). Furthermore, the crystal structures of 7, 8 and 9 reveal interesting porous energetic coordination polymers with strong hydrogen bond interactions. All new salts have good thermal stabilities with decomposition temperature between 215.0 °C (4) and 328.2 °C (7), significantly higher than that of the reported nitrogen-rich salt neutral tetrazolone. The sensitivities towards impact and friction were tested using standard methods, and all the tetrazolone-based compounds investigated can be classified into insensitive. The flame test of these metal salts supports their potential use as perchlorate-free pyrotechnics or eco-friendly insensitive energetic materials.
- He, Piao,Wu, Le,Wu, Jin-Ting,Yin, Xin,Gozin, Michael,Zhang, Jian-Guo
-
p. 8422 - 8430
(2017/07/12)
-
- Reactions of dimethyl 2-chloroethynylphosphonate with 1-substituted 5-oxo-1H-1,2,3,4-tetrazoles
-
Addition of 1-substituted tetrazol-5-ones to dimethyl 2-chloroethynylphosphonate occurred regioselectively to form new geminally substituted bis(4-R-5-oxo-4,5-dihydro-1H-tetrazol-1-yl)ethenylphosphonates with 65- 92% yield.
- Mel'nikova,Myznikov,Dogadina,Svintsitskaya
-
p. 2160 - 2166
(2015/02/02)
-
- Process for the preparation of 1-4-disubstituted-5 (4H)-tetrazolinones
-
1,4-Disubstituted-5(4H)-tetrazolinones of the formula (I) STR1 wherein R1, R2 and R3 have the meanings given in the specification), which are known to be useful as herbicides, can be obtained in very good yields by reacting the corresponding 1-substituted-5(4H)-tetrazolinones with the corresponding carbamoyl chlorides in the presence of 4-dimethylaminopyridine.
- -
-
-
- Synthetic 1,4-Disubstituted-1,4-dihydro-5H-tetrazol-5-one Derivatives of Fentanyl: Alfentanil (R 39209), a Potent, Extremely Short-Acting Narcotic Analgesic
-
The synthesis of a series of N-1,4-disubstituted-1,4-dihydro-5H-tetrazol-5-one piperidinyl derivatives of fentanyl (10), carfentanil (11), and sufentanil (12) is described.The 1-substituted tetrazolinones 2 were essentially prepared via the addition reaction of aluminum azide to isocyanates or acid chlorides in tetrahydrofuran.Alkylation of 2 under neutral or weakly basic conditions afforded almost exclusively the 1,4-disubstituted tetrazolinone isomer 3.N-Alkylation of the piperidine derivatives 4 with 3 in dimethylformamide yielded 9a-v.The morphinomimetic activity in rats, after intravenous injection of the compounds, was evaluated in the tail withdrawal reflex test.The fentanyl analogues 9a-c (R4 = H) are inactive at the measured dose of 2.5 or 10 mg/kg (iv).For the carfentanil analogues (R4 = COOCH3) maximal narcotic activity is found when R1 represents a lower alkyl group (9d-f) or a thienylethyl group (9n).The sufentanil analogues (R4 = CH2OCH3) show the same structure-activity relationship (SAR) profile as the carfentanil derivatives (R4 = COOCH3).The structural requirements for optimal activity are in good agreement with earlier observations in the series of 10-12.From the series the ethyl tetrazolinone derivative 9r, alfentanil (R 39209), was selected for clinical investigation.As an analgesic in rats, 9r is 140 times more potent then pethidine 15 and 72 times more potent than morphine 14.Alfentanil reaches its peak effect within 1 min after injection, and its duration of action is very short; at 2 times its MED50, 9r has a duration of action of 11 min.This duration is 30 min for 10 and 90 min for 14.Compared to 10, alfentanil 9r is about 4 times faster but 3 times shorter acting.Structurally, 9r shows most resemblance to sufentanil 12, since it differs only by substitution of a 4-ethyltetrazolinone ring for the thiophene ring.The considerable differences in their pharmacological profiles were explained in terms of marked variations in physicochemical and, hence, pharmacokinetic properties.
- Janssens, Frans,Torremans, Joseph,Janssen, Paul A.J.
-
p. 2290 - 2297
(2007/10/02)
-
- N-phenyl-N-(4-piperidinyl)amides
-
Novel compounds of the series of N-phenyl-N-(4-piperidinyl)amides having a (4,5-dihydro-4-R-5-oxo-1H-tetrazol-1-yl)alkyl or (4,5-dihydro-4-R-5-thioxo-1H-tetrazol-1-yl)alkyl substituent group in the 1-position of the piperidine nucleus, said compounds being useful as analgesic agents.
- -
-
-