Enanthic anhydride

A. Heptoic anhydride enanthic anhydride). In a 250-ml. round-bottomed three-necked flask, equipped with a stirrer, dropping funnel, and thermometer, are placed 15.8 g. (16.1 ml., 0.2 mole) of dry pyridine (Note 1) and 25 ml. of dry benzene (Note 2). I hen 14.8 g. (15.5 ml., 0.1 mole) of heptoyl chloride (Note 3) is added rapidly to the stirred solution. The temperature rises only slightly, and a pyridinium complex separates. While stirring is continued, 13.0 g. (14.1 ml., 0.1 mole) of heptoic acid (Note 3) is added from the dropping funnel over a period of 5 minutes. The temperature rises rapidly to 50-65° (Note 4), and pyridine hydrochloride is formed. After stirring for 10 minutes, the solid is collected on a chilled Buchner funnel and washed twice with 25-ml. portions of dry benzene (Note 5). 

Synonyms Carboxylic acid C7 Enanthic acid Enanthic anhydride Enanthylic acid n-Heptanoic acid... 

Norethindrone may be recrystakhed from ethyl acetate (111). It is soluble in acetone, chloroform, dioxane, ethanol, and pyridine slightly soluble in ether, and insoluble in water (112,113). Its crystal stmcture has been reported (114), and extensive analytical and spectral data have been compiled (115). Norethindrone acetate can be recrystakhed from methylene chloride/hexane (111). It is soluble in acetone, chloroform, dioxane, ethanol, and ether, and insoluble in water (112). Data for identification have been reported (113). The preparation of norethindrone (28) has been described (see Fig. 5). Norethindrone acetate (80) is prepared by the acylation of norethindrone. Norethindrone esters have been described ie, norethindrone, an appropriate acid, and trifiuoroacetic anhydride have been shown to provide a wide variety of norethindrone esters including the acetate (80) and enanthate (81) (116). 

Horse-radish peroxidase has been treated with acetic, butyric, valeric, enanthic, and succinic anhydrides of mono- and di-carboxylic acids, and with picrylsulphonic acid. ° The effects of these modifications on catalytic activity, rates of irreversible thermal inactivation, and absorption and c.d. spectra were studied. The degree of modification rather than the nature of the modifier was found to be responsible for the major effect on the macromolecular conformation and thermostability of the enzyme after modification. 

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