(1,2,4)Triazolo(1,5-a)pyrazine

Polyphosphoric acid (250 g) was added to (Z)-N'-hydroxy-N-(pyrazin-2-yl)-formimide amide (25.07 g, 181 mmol), and the reaction mixture was then immediately heated to 90° C. The mixture was stirred for 4 h, and the hot reaction mixture was poured into ice-water and rendered basic with sodium hydrogen carbonate. The aqueous phase was extracted with dichloromethane (1 l, 3.x.0.5 l), and the combined organic phases were dried (NaA mixture of the above solid (1.9 g, 13.8 mmol)and PPA (15 mL) was heated to 90° C. for 6 h and was then diluted with ice-water and the pH was adjusted to 8 with aqueous ammonia solution and NaHC03. The mixture wasthen extracted with 10percent MeOH in CH2C12. The organic layerwas dried (Na2SO4), filtered and concentrated in vacuo to give the desired compound as off-white solid (1.2 g, 75percent yield, which was used directly for the next step). MS: (ES) m/z 121.1 (M+HStage 3. Polyphosphoric acid (250 g) was added to the N' - hydroxy-N- (pyrazin-2-yl) formimidamide (25.07 g, 181 mmole), whereupon the temperature rose to 9O0C. The reaction mixture was stirred for 4 hours . The hot reaction solution was then added to iced water and adjusted alkaline with sodium hydrogen carbonate solution. The aqueous phase was extracted with DCM (1 litre, 2 x 0.5 litre) and the combined organic phases were dried over sodium sulfate. The organic phase was concentrated by evaporation to dryness and the product was crystallised from ethanol. The mother liquor was again concentrated by evaporation and the product was crystallised once more from ethanol.Polyphosphoric acid (250 g) was added to (Z)-N'-hydroxy-N-(pyrazin-2-yl)-formimide amide (25.07 g, 181 mmol), and the reaction mixture was then immediately heated to 90 C. The mixture was stirred for 4 h, and the hot reaction mixture was poured into ice-water and rendered basic with sodium hydrogen carbonate. The aqueous phase was extracted with dichloromethane (1 l, 3×0.5 l), and the combined organic phases were dried (Na2SO4) and concentrated. The crude product was crystallized from ethanol in several batches. Yield: 18.10 g (83%)Platinum(IV) oxide (2.75 g, 12.1 mmol) was added, under nitrogen, to a suspension of calcium oxide (9.30 g, 166 mmol) and Step D: 5, 6, 7, 8-Tetrahydrof 1, 2, 41triazolof 1, 5-alpyrazine; A mixture of [l, 2, 4]triazolo[l, 5-a]pyrazine (10 g) in ethanol (150 mL) and 10% Pd-C (3 g) was stirred under a hydrogen atmosphere overnight and filtered over Celite. The filtrate was evaporated and the residue purified by column chromatography (silica, 10% methanol/dichlorornethane) to yield 5, 6, 7, 8-tetrahydro[l, 2, 4]triazolo[l, 5-a]pyrazine. LC-MS 125.1 (M+ 1).Stage 4. Platinum (IV) oxide (2.75 g, 12.1 mmole) was added to a suspension, saturated with nitrogen, of CaO (9.30 g, 166 mmole) and [ 1, 2 , 4 ] -triazolo [ 1, 5-a] pyrazine (18.1 g, 151 mmole) in methoxyethanol (150 ml) . The reaction mixture was stirred for 21.5 hours under a hydrogen atmosphere. The catalyst was filtered off through filter earth and washed with DCM/ethanol (9:1). The filtrate was concentrated, and the solvent was removed firstly with

Molecular Weight:120.11
XLogP3:-0.3
Hydrogen Bond Acceptor Count:3
Exact Mass:120.043596145
Monoisotopic Mass:120.043596145
Topological Polar Surface Area:43.1
Heavy Atom Count:9
Complexity:105
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes