HCID 311825, compound → HCID 14495955, compound
Reaction equation
Cl[C:2]1[C:7](Cl)=[N:6][C:5]2=[N:9][S:10][N:11]=[C:4]2[N:3]=1.[C:12]1(=[O:22])[NH:16][C:15](=[O:17])[C:14]2=[CH:18][CH:19]=[CH:20][CH:21]=[C:13]12.[K]>CN(C)C=O>[C:12]1(=[O:22])[N:16]([C:2]2[C:7]([N:16]3[C:15](=[O:17])[C:14]4=[CH:18][CH:19]=[CH:20][CH:21]=[C:13]4[C:12]3=[O:22])=[N:6][C:5]3=[N:9][S:10][N:11]=[C:4]3[N:3]=2)[C:15](=[O:17])[C:14]2=[CH:18][CH:19]=[CH:20][CH:21]=[C:13]12Participants
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Procedure
The cyclization reaction of o-diaminobenzene (compound II) in an aqueous solution of glyoxal and sodium hydrogen sulfite gives quinoxaline (compound III; See R. G. Jones et al., Org. Syn. Collective Vol. IV, page 824). Quinoxaline is in turn oxidized by an aqueous solution of potassium permanganate to produce 2,3-pyrazinedicarboxylic acid (compound IV; See R. G. Jones et al., Org. Syn. Collective Vol. IV, page 824). 2,3-pyrazinedicarboxylic acid is then chlorinated with phosphorus pentachloride at 300° C. to produce 2,3,5,6-tetrachloropyrazine (compound V; See C. G. Allison et al., J. Chem. Soc. (C), 1970, page 1023). The reaction of 2,3,5,6-tetrachloropyrazine with ammonium chloride at a temperature of 120° C. gives 2,3-diamino-5,6-dichloropyrazine (compound VI; See Palamidess et al., Ed. Sc. XXI-fasc, 11, 1966, page 810). The cyclization reaction of 2,3-diamino-5,6-dichloropyrazine with thionyl chloride in the presence of pyridine in xylene produces 5,6-dichloro-[1,2,5]thiadiazolo[3,4-b]pyrazine (compound VII; See Y. C. Tong, J. Heterocyclic Chem., 12, 1975, page 451 ). The 5,6-dichloro-[1,2,5]thiadiazolo[3,4-b]pyrazine is reacted with potassium phthalimide in the presence of dimethyl formamide (DMF) at a temperature of 60° C. to produce 5,6-diphthalimido[1,2,5]thiadiazolo[3,4-b]pyrazine (compound VIII; See Example 1). The 5,6-diphthalimido-[1,2,5]thiadiazolo[3,4-b]pyrazine is then reacted with an aqueous solution of hydrazine at 0° C. to produce 5,6-diamino-[1,2,5]thiadiazolo[3,4-b]pyrazine (compound IX; See Example 2). Finally the cyclization reaction of 5,6-diamino[1,2,5]thiadiazolo[3,4-b]pyrazine with thionyl chloride in the presence of pyridine in methylene chloride gives bis[1,2,5]thiadiazolo[3,4-b:3',4'-e]pyrazine (compound I; See Example 3).
Sources & evidence
- ORD record
- ord-0c0faca8d40c47ffa16271051a20b252
- Source dataset
- uspto-grants-1990_05
- Patent number
- US04929730
Reaction notes
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