Formaldehyde → 6-Methoxy-3,4-dihydro-1H-2-benzopyran-1-one

참여 물질

반응 단계

To a solution of diisopropylamine (33.5 ml) in dry THF (190 ml) was added dropwise, at −78° C., n-butyllithium (1.6 M solution in hexane, 145.9 ml). Subsequently, the reaction mixture was warmed to room temperature for 5 minutes and then cooled again to −78° C., and a solution of 4-methoxy-2-methylbenzoic acid (10 g) in dry THF (210 ml) was added dropwise. After stirring at this temperature for 10 minutes, paraformaldehyde (7 g) was added. The reaction mixture was then allowed to come to room temperature and stirred at this temperature for 4 hours. The reaction mixture was admixed with water, then the THF was removed under reduced pressure and then the aqueous phase was extracted with diethyl ether. The aqueous phase was acidified with conc. HCl, and the resulting precipitate was filtered off and washed repeatedly with water. The product was thus obtained with the molecular weight of 178.06 (C10H10O3); MS (ESI): 179 (M+H+).

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