| 摘要 |
1301188 Nitrofuran derivatives R & L MOLECULAR RESEARCH Ltd 22 April 1970 [24 April 1969] 19367/70 Heading C2C [Also in Division A5] The novel compounds, methyl and ethyl 5- (5-nitro - 2 - furyl) - 3 - methylisoxazole - 4- carboxylates, are prepared by (a) treating methyl or ethyl 5-(2-furyl)-3-methylisoxazole- 4-carboxylate with an excess of a nitrating agent comprising a mixture of nitric acid and acetic anhydride, or (b) reacting methyl or ethyl acetoacetate with 5-nitrofuryl chloride and treating the resulting methyl or ethyl α-(5-nitrofuroyl)-acetoacetate with hydroxylamine hydrochloride or sulphate. Ethyl 5-(5-nitro-2-furyl)- 3-methylisoxazole-4-carboxylate can also be prepared by treating methyl 5-(5-nitro-2-furyl)- 3-methylisoxazole-4-carboxylate with a mixture of hydrochloric and acetic acids to form the corresponding acid, reacting the acid with thionyl chloride to form the acid chloride, and reacting the acid chloride with ethanol. Methyl and ethyl 5-(2-furyl)-3-methylisoxazole 4-carboxylates are prepared by reacting methyl or ethyl acetoacetate with furoyl chloride and treating the resulting methyl or ethyl α-furoylacetoacetate with hydroxylamine hydrochloride |
