PYRAZIN-2-YL-HYDRAZINE

Pale yellow solid

Step 1: 2-hydrazinylpyrazine [0204] 2-Chloropyrazine (2.0 g, 17.5 mmol) was added dropwise to a 35percent aqueous solution of hydrazine hydrate (25.8 g, 97.8 mmol) at 63-65 °C, the addition rate was carefully monitored to ensure that the reaction temperature did not exceed 65 °C. Following the addition, the mixture was heated to 65 °C. After stirring overnight, the reaction was cooled to room temperature. The solvent was evaporated to afford the title compound as a yellow powder (1.5 g, 75percent). MS (ESI) calcd for CGeneral procedure: (0.1mole) of 2-halo nitrogen heterocycle and (0.5 mole) of hydrazine hydrate were mixed together in a 250mL round bottom flask equipped with reflux condenser and wereheated at 100A mixture of 2-chloropyrazine (4.00 g) andhydrazine hydrate was heated at 1 10 °C for 1 h, and then cooled to room temperature. The mixture was filtered to give the title compound as a solid (2.30 g, 60.00 percent). The compound was characterized by the following spectroscopic data: MS (ESI, pos. ion) m/z: 1 1 1.0 (M+ l).A mixture of 2-chloropyrazine (4.00 g) and hydrazine hydrate was heated at 110° C. for 1 h, and then cooled to room temperature. The mixture was filtered to give the title compound as a solid (2.30 g, 60.00percent). The compound was characterized by the following spectroscopic data: MS (ESI, pos. ion) m/z: 111.0 (M+1).1)Will be 31.3 grams(80 wtpercent, 50 mmol)Hydrazine hydrate was added to 100 ml three-necked flask, Heating up to 60 , Under magnetic stirring, 11.5 g was slowly added dropwise(100 mmol)2-chloropyrazine, The reaction was carried out at a temperature of 60 ° C for 10 hours, After completion of the reaction, the mixture was cooled to 2 ° C, Precipitation of solids, filter, Dried to afford 6.63 g of a white solid, Yield 60.5percent;The reaction was run under nitrogen atmosphere. 2-chloropyrazine (96 mL, 1073 mmol) was added dropwise to 35 wt aqueous hydrazine (544 mL, 6009 mmol) at 65 °C over 1 h. After the addition, stirring was continued at 63-67 °C for 16 h then let stand at room temperature for two days. The mixture was filtered to remove a small amount of precipitate, then extracted with 10percent iPrOH/dichloromethane (5 x 250 mL). The combined organic extracts were dried (MgS0[Referential Example 33] 2-Hydrazinopyrazine; Hydrazine monohydrate (21.80 g) was added to a solution of 2-chloropyrazine (10.44 g) in ethanol (65 ml) at room temperature, and the mixture was heated under reflux for 17 hours. After cooling with air, the reaction solvent was evaporated under reduced pressure, and benzene was added to the residue, then the insoluble content was' removed by decantation. After evaporation of the benzene solution under reduced pressure, hexane was added to the resulting solid, and the product was collected by filtration to give the title compound (4.67 g, 47percent). [Referential Example 2] 2-Hydrazinopyrazine Hydrazine monohydrate (21.80 g) was added to 2-chloropyrazine (10.44 g) in ethanol (65 mL) at room temperature, and the resultant mixture was refluxed for 17 hours, followed by cooling in air. The reaction solvent was evaporated under reduced pressure, and then benzene was added to the residue. The resultant mixture was subjected to decantation, to thereby remove an insoluble matter. The benzene was evaporated under reduced pressure. Hexane was added to the resultant solid, and the mixture was subjected to filtration, to thereby give the title compound (4.67 g, 47percent). Using Procedure AU-3 (Table 5) with 2-chloropyrazine the title compound 476 was obtained (4.4 g, 46percent) as a yellow solid. MS (m/z): 111.0 (M+H)20.0 g (174.6 mmol) 2-chloropyrazine are added dropwise to 60.0 ml (61.7 g, 1.2 mol) hydrazine hydrate. The mixture is stirred at a bath temperature of 120° C. for 45 min. For working up, the cooled reaction mixture is left to stand at 2° C. for 12 h, the crystals which have precipitated out are filtered off and the residue on the filter is washed twice with petroleum ether. The residue is then recrystallized from toluene.Yield: 6.5 g (34percent of th.)LC-MS (Method 1): R20.0 g (174.6 mmol) of chloropyrazine are added dropwise to 61.7 g (1.2 mol) of hydrazine hydrate, and the mixture is stirred at 120° C. for 45 min. The mixture is then allowed to stand at 2° C. for 24 h. The solid is filtered off and washed twice with petroleum ether. The solid is initially air-dried and then dried under high vacuum. The solid is then recrystallized from toluene and again dried under high vacuum.Yield: 6.5 g (34percent of theory)LC-MS (Method 1): R

Molecular Weight:110.12
XLogP3:-0.2
Hydrogen Bond Donor Count:2
Hydrogen Bond Acceptor Count:4
Rotatable Bond Count:1
Exact Mass:110.059246208
Monoisotopic Mass:110.059246208
Topological Polar Surface Area:63.8
Heavy Atom Count:8
Complexity:65.1
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes