Phosphoric Acid → HCID 19073514, compound

Participants

Reaction Steps

53 ml of the solution of 1-chloro-1-(N-hydroxyimino)ethane 45 described above and 6.3 ml of triethylamine are added with stirring at 0° C. to a solution of 8.0 g of 2,2-dimethyl-5-(ethynyl)-4H-(1,3)benzodioxin-4-one in 400 ml of methyl tert-butyl ether, and the mixture is allowed to come to room temperature and is subsequently stirred overnight. A further 53 ml of the solution of 1-chloro-1-(N-hydroxyimino)ethane described above and 6.3 ml of triethylamine are added and the reaction solution is stirred at room-temperature for 24 h. It is then poured into water containing phosphoric acid (pH 4) at 0° C. and extracted with methyl tert-butyl ether, and the combined organic phases are carefully washed with water, dried over sodium sulfate and concentrated. 8.8 g of crude product remain, which is chromatographed on silica gel using n-hexane/ethyl acetate. 4.1 g of colorless crystals are obtained, m.p. 74° C. (cf. Table 1, No. 1.020).

Provenance & Evidence