1,1-Diethylguanidine → 2-Amino-8-diethylamino-4,5-dihydrothiazolo[4,5-h]quinazoline

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Reaction Conditions

Reaction Steps

To N′-{6-[1-dimethylamino-meth-(E)-ylidene]-7-oxo-4,5,6,7-tetrahydro-benzothiazol-2-yl}-N,N-dimethyl-formamidine (Stage A.2, 1 g, 3.59 mmol) in 2-methoxyethanol (10 mL) was added NaOH (0.539 g, 13.47 mmol) and N,N-diethylguanidine (0.454 g, 3.94 mmol) under argon at rt. The RM was stirred for 3.5 h at 125° C. and then cooled to rt. After evaporation in vacuo the residue was dissolved in 0.1 M HCl (50 mL) and washed with EtOAc. The aqueous layer was then basified with 6 N NaOH and extracted 3× with EtOAc. the organic layers were dried over Na2SO4, evaporated and dried under high vacuum at 60° C. to give the title compound as orange crystals. LC: tR 3.60 min (method D). MS: M+H=276. 1H-NMR in DMSO-d6: 7.91 (s, 1H); 7.59 (s, 2H); 3.50 (q, 4H); 2.69 (dd, 4H); 1.07 (t, 6H).

Provenance & Evidence