* All experimental methods are cited from the reference, please refer to the original source for details. We do not guarantee the accuracy of the content in the reference.
Stage #1: With platinum(IV) oxide; palladium 10% on activated carbon; hydrogen In methanol for 34 h; Stage #2: With N-ethyl-N,N-diisopropylamine In methanol at 20℃; for 3 h;
After dissolution compound obtained in Step 2 (8.10 g) and platinum oxide (IV) and 10percent palladium / carbon (2g, 50percent water content) in methanol (8 mL), under an atmosphere of hydrogen 50psi (Parr) 34 time and stirred. After filtering the reaction solution at Hyflo Super Cel, the oil obtained by concentrating the solvent was dissolved in dichloromethane (200 mL), N, N-diisopropylethylamine (10 mL) and di-tert-butylcarbonate (11 .4g) was added was stirred for 3 hours at room temperature. The reaction solution was extracted three times with chloroform after adding a saturated aqueous sodium hydrogen carbonate solution, and the organic layer was concentrated after dried over sodium sulfate. The resulting residue to give the title compound purified by silica gel column chromatography (2.55g, 22percent).
[1-(3,4-difluoro-benzyl)-3-(5,6-dihydro-8<i>H</i>-[1,2,4]triazolo[4,3-<i>a</i>]pyrazin-7-yl)-3-oxo-propyl]-carbamic acid <i>tert</i>-butyl ester[ No CAS ]
It was stirred for 4 hours at reflux mixture of the compound obtained in Step 1 (8 g) and triethyl orthoformate (32 mL). The reaction solution was cooled to room temperature, the precipitated solid was washed after filtration, with ethanol, To give the title compound followed by drying under reduced pressure (8.10g, 95%).
90.1%
at 80.0℃;
Intermediate b (5.0 g, 0.034 mol) was added to triethyl orthoformate (50 mL), and the reaction was carried out at 80 C. The reaction time was monitored with a plate. The reaction liquid was directly filtered with cold suction, and the filter cake was washed with petroleum ether. After the cake was dried, 4.8 g of a yellow powder was obtained with a yield of 90.1%.
90.1%
at 80.0℃;
Intermediate b (5.0 g, 0.034 mol) was added to triethyl orthoformate (50 mL), and the reaction was carried out at 80 C. The reaction time was monitored with a plate. The reaction liquid was directly filtered with cold suction, and the filter cake was washed with petroleum ether. After the cake was dried, 4.8 g of a yellow powder was obtained with a yield of 90.1%.
62%
In xylene; for 2h;Heating / reflux;
A mixture of l-(3-chloropyrazin-2-yl)hydrazine (0.90 g, 62 mmol), triethyl orthoformate (2.3 mL), 14 mmol), and dry xylene (15 mL) was refluxed with stirring for 2 h. The mixture was brought to RT, diethyl ether was added and the suspension was filtered. The solid collected was washed with diethyl ether to afford 8-chloro-[l,2,4]triazolo[4,3- ajpyrazine (0.60 g, 62% yield). MS m/z: 155.0 (M+l).
62%
In xylene; for 2h;Reflux;
Step 3: 8-chloro-[1,2,4]triazolo[4,3-a]pyrazine A mixture of 1-(3-chloropyrazin-2-yl)hydrazine (0.90 g, 62 mmol), triethyl orthoformate (2.3 mL), 14 mmol), and dry xylene (15 mL) was refluxed with stirring for 2 h. The mixture was brought to RT, diethyl ether was added and the suspension was filtered. The solid collected was washed with diethyl ether to afford 8-chloro-[1,2,4]triazolo[4,3-a]pyrazine (0.60 g, 62% yield). MS m/z: 155.0 (M+1).
Chemistry
Pharmaceutical Intermediates
Inhibitors/Agonists
Material Science
For Research Only
120K+ Compounds
Competitive Price
1-2 Day Shipping
