Water → 6-Chloro-2-(methoxymethyl)imidazo[2,1-b][1,3,4]thiadiazole

Participants

Reaction Conditions

Reaction Steps

To {2-[(tert-butoxycarbonyl)imino]-5-(methoxymethyl)-1,3,4-thiadiazol-3(2H)-yl}acetic acid a33 (418 g, 1.378 mol, 1 eq) in acetonitrile (2.51) at room temperature, are successively and slowly added triethyl amine (278.9 g, 2.756 mol, 2 eq), then phosphorous oxychloride (633.9 g, 4.134 mol, 3 eq). The reaction mixture is heated at 80° C. for one hour. After reaction completion, water (2.2 l) is slowly and carefully added at 50° C. The reaction mixture is extracted with dichloromethane (2×1.21), the combined organic layers are washed by a NaOH/NaCl aqueous solution (1.4 l of saturated NaCl solution+400 ml 2N NaOH), dried over MgSO4, filtered and condensed under reduced pressure. The residue is recrystallized from acetonitrile/water (1/1) to afford 99.8 g of pure 6-chloro-2-(methoxymethyl)imidazo[2,1-b][1,3,4]thiadiazole a35.

Provenance & Evidence