These common heterocyclic compound, 54608-52-5, name is 2-Hydrazinopyrazine, its traditional synthetic route has been very mature, but the traditional synthetic route has various shortcomings, such as complicated route, low yield, poor purity, etc, below Introduce a new synthetic route. category: Pyrazines
Step C: Preparation of (laS,5aS)-2-(Pyrazin-2-yl)-la,2,5,5a-tetrahydro-lH-2,3- diaza-cyclopropa[a]pentalene-4-carboxylic Acid Ethyl Ester. Method KKKTo a solution of (lS,5R)-bicyclo[3.1.0]hexan-2-one (52.9 g, 539 mmol) and diethyl oxalate (0.073 L, 539 mmol) in absolute ethanol (0.9 L) (not denatured with methanol) was added a THF solution of potassium tert-butoxide (1.0 M, 0.539 L, 539 mmol) over 15 min (maintaining the temperature below 43 C). The resulting yellow solution was stirred at 40 C for 3.5 h. 2-Hydrazinylpyrazine (59.4 g, 539 mmol) was added followed by a 6.0 M aqueous solution of hydrogen chloride (0.270 L, 1618 mmol). The reaction was stirred at 50 C for 1.5 h. The mixture was poured into ice -water (5 L). A precipitate appeared immediately. After sitting for 30 minutes in an ice bath, the solid was collected by filtration, rinsed with water (5 x 1 L), and dried to give the title compound (106 g) as an off-white solid .H NMR. LCMS m/z = 271.2 [M+H]+; lU NMR (400 MHz, CDC13) delta 0.47 (td, 7 = 4.7, 3.3 Hz, 1H), 1.27 (td, 7 = 8.0, 4.9 Hz, 1H), 1.41 (t, 7 = 7.1 Hz, 3H), 2.26-2.32 (m, 1H), 2.77-2.82 (m, 1H), 2.88 (dd, 7 = 16.7, 1.4 Hz, 1H), 2.99 (dd, 7 = 16.6, 6.4 Hz, 1H), 4.40 (q, 7 = 7.1 Hz, 2H), 8.41 (dd, 7 = 2.5, 1.5 Hz, 1H), 8.52 (d, 7 = 2.5 Hz, 1H), 9.40 (d, 7 = 1.5 Hz, 1H).
The synthetic route of 2-Hydrazinopyrazine has been constantly updated, and we look forward to future research findings.
Reference:
Patent; ARENA PHARMACEUTICALS, INC.; THATTE, Jayant; BLACKBURN, Anthony C.; HAN, Sangdon; JONES, Robert M.; JUNG, Jae-Kyu; MONTALBAN, Anthony Garrido; PAL, Biman B.; RUETER, Jaimie Karyn; STRAH-PLEYNET, Sonja; THORESEN, Lars; XIONG, Yifeng; YUE, Dawei; ZHU, Xiuwen; WO2012/116279; (2012); A1;,
Pyrazine – Wikipedia,
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