天然热喷泉
发表于 2025-3-23 13:05:20
2-Methylfuran (Sylvan),ranching from a high point on the neck; 63 g (0.5 mole) of 5-methyl-2-furoic acid (see p. 33), m.p. 108–109°, was placed in the flask. The mouth of the flask was closed with a stopper carrying a long glass rod B, which was used for clearing the neck from 5-methyl-2-furoic acid sublimate. The side tu
点燃
发表于 2025-3-23 14:44:38
,-Propylfurfuryl Alcohol, introduced into a 500-ml three-necked round-bottomed flask fitted with mercury-sealed stirrer, dropping funnel, and reflux condenser protected by a calcium chloride tube. A solution of 32 g (0.26 mole) of freshly distilled propyl bromide in 100 ml of dry ether was added dropwise from the dropping f
STALE
发表于 2025-3-23 21:31:19
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抵制
发表于 2025-3-23 23:09:08
Furan,lmost to the bottom of the flask. The mouth of the flask is closed with a rubber bung through which passes the vertical tube C, 15 cm in length and 1.8–2.0 cm in diameter. The upper end of the tube C is closed with a rubber stopper, which carries a long glass rod D; this is used for pushing sublimed
花束
发表于 2025-3-24 05:41:48
Methyl 5-(Chloromethyl)-2-Furoate, avoid resinification, the flask was cooled with water so as to prevent the temperature from rising above 24–26°. The reaction lasted about two hours; the end of the reaction was indicated by the complete dissolution of the para-formaldehyde: the spontaneous evolution of heat gradually stopped, and the mixture became light yellow in color.
删除
发表于 2025-3-24 07:34:58
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独特性
发表于 2025-3-24 12:46:44
,-Phenylfurfuryl Alcohol,til dissolution of the magnesium was substantially complete. The contents of the flask were then cooled with ice and salt and were stirred continuously for 40–50 minutes while a solution of 27.3 g (0.27 mole) of freshly distilled 2-furaldehyde in 150 ml of dry ether was added.
negotiable
发表于 2025-3-24 15:41:04
Methyl 5-Benzyl-2-Furoate, and cooled with ice water for two hours while 40 g (0.3 mole) of anhydrous aluminum chloride was added in small portions. When the vigorous reaction ceased, the mixture was heated in a water bath (temperature of bath 80–85°) for 4–5 hours (see Notes).
harangue
发表于 2025-3-24 22:43:33
of investigation in this field is due largely to the ever increasing practical importance of heterocyclic com pounds. The present stage in the development of organic chemistry and closely allied branches of biology is characterized by extensive investigation of physiologically active substances en
ROOF
发表于 2025-3-25 02:05:55
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