4-(4,5-Dihydro-1,3-oxazol-2-yl)phenol → HCID 490094, compound

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Reaction Steps

A solution of 2-chloro-5-(5-chloropentanoyl)thiophene (3c) (1.18 g, 0.005 mol) and aluminum trichloride (0.66 g, 0.005 mol) in anhydrous ethyl ether (40 ml) and tetrahydrofuran (30 ml) was slowly added to a mixture, cooled to 0°-5° C., consisting of lithium and aluminium hydride (1.33 g, 0.01 mol) in anhydrous ethyl ether (40 ml). The reaction mixture was magnetically stirred for 6 hrs. at 30°-40° C., cooled to 0°-5° C., and cautiously diluted with water (20 ml) and 6N hydrogen sulphate (20 ml). The organic phase was separated, washed with water, and dried on anhydrous sodium sulphate. Solvent removal gave a chromatographically pure liquid residue (TCL: silicon dioxide-cyclohexane) consisting of 7 (0.99 g; 89%), which was directly used in the subsequent reaction with 2-(4-hydroxyphenyl)-4,5-dihydro-oxazole, as described for the preparation of 4c, to give 9 (0.81 g; 52%) (after crystallization via cycloexane). M.p. 99°-100° C. Anal. (C18H20ClNO2S).

Provenance & Evidence