L-Methionine → HCID 135816633, compound

HRID 727781Notes

Reaction equation

N[C@H](C(O)=O)CCSC.C[O:11][C:12]1[CH:13]=[CH:14][C:15]2[C:24]3[CH:19]([CH2:20][C:21](=[O:31])[N:22]([C:25]4[CH:30]=[CH:29][CH:28]=[CH:27][N:26]=4)[N:23]=3)[CH2:18][CH2:17][C:16]=2[CH:32]=1.C(=O)([O-])[O-].[K+].[K+]>CS(O)(=O)=O>[OH:11][C:12]1[CH:13]=[CH:14][C:15]2[C:24]3[CH:19]([CH2:20][C:21](=[O:31])[N:22]([C:25]4[CH:30]=[CH:29][CH:28]=[CH:27][N:26]=4)[N:23]=3)[CH2:18][CH2:17][C:16]=2[CH:32]=1

Participants

Conditions

Temperature: 55 °C

Procedure

A mixture of 1.0 g of methionine, 70 ml of methanesulfonic acid and 10 g of 8-methoxy-2-(2-pyridyl)-4,4a,5,6-tetrahydrobenzo[h]cinnolin-3(2H)-one is stirred at 55° C. for 26 hours. The reaction mixture is poured into ice-water, and the mixture is neutralized with potassium carbonate and extracted with chloroform. The extract is washed with an aqueous solution of sodium chloride and dried over magnesium sulfate. After the solvent is distilled off under reduced pressure, the residue is purified by silica gel chromatography (chloroform:methanol =10:1) and recrystallized from chloroform methanol to give 2.7 g of 8-hydroxy-2-(2-pyridyl)-4,4a,5,6-tetrahydrobenzo[h]cinnolin-3(2H)-one as white crystals, m.p. 193°-194° C.

Workup

extractionextracted with chloroform
washThe extract is washed with an aqueous solution of sodium chloride
dry with materialdried over magnesium sulfate
distillationAfter the solvent is distilled off under reduced pressure
customthe residue is purified by silica gel chromatography (chloroform:methanol =10:1)
customrecrystallized from chloroform methanol

Sources & evidence

ORD record: ord-254f9fa052df4fe9a32c05723c67ec3b
Source dataset: uspto-grants-1991_09
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05045541

Reaction notes

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