Phosgene → 4-(4-methoxyphenyl)-alpha-methyl-4H-1,2,4-triazol-3-methanol

Participants

Reaction Conditions

Reaction Steps

2.36 g of triethylamine were added to a suspension of 5 g of 4-dimethylamino-4-methoxy benzanilide (prepared as in Example 12) in 50 ml of methylene chloride and the mixture was cooled to -40° C. Then over 20 minutes and under an inert atmosphere, a solution of 5.75 ml of phosgene in toluene is added, and the mixture was re-heated to 20° C. over 90 minutes. The solution obtained was introduced into 200 ml of refluxing toluene and simultaneously a solution of 2.9 g of lactic acid hydrazide (DL form) in 6 ml of dimethylformamide was added. A part of the solvents was eliminated by distilling and then, after heating for 30 minutes to 107°-110° C., the reaction mixture was cooled and washed first with water, then with an N aqueous solution of sodium hydroxide and again with water. After extracting with methylene chloride and concentrating to dryness, 7.1 g of crude product were obtained which was crystallized from a mixture of ethyl acetylacetate and isopropyl ether (3-6) and then from pure ethyl acetate to obtain 5-[4-dimethylamino)phenyl]-4-(4-methoxyphenyl)-α-methyl-4H-1,2,4-triazol-3-methanol melting at 170° C.

Provenance & Evidence