Chemistry in the Iowa Academy of Science

As indicated in Table I, a preliminary meeting looking toward the organization of an academy of science in Iowa was held in Iowa City in 1875. According to the records three professors and four doctors were present at the meeting. Two of the professors were from Ames and one from Iowa City, while Ames, Iowa City, Davenport and Des Moines were represented by the four medical men. Five other persons, two of whom were in academic work and three in medical practice, stationed at Iowa City, Tabor, Clinton, Davenport and Dubuque, respectively, had previously expressed their approval of the proposed organization, and they, together with the ones previously named were designated as charter members. At the first regular meeting, which was held in Des Moines, articles of incorporation were approved, a proposed constitution was reported, five fellows were elected, and papers were read. At the first annual meeting held in June, 1876, a constitution was adopted, and a program presented

Effect of Substituents in the Formation and Reactions of Certain Ethers

48. Effect of substituents In a previous report on this study it was found by Raiford and Colbert [Jour. Am. Chem. Soc., 48, 2652 (1926)] that the presence of a nitro radical in diphenyl ether interferes with the entrance of bromine to a much greater degree than could have been predicted on the ground of steric hindrance. Owing to lack of time the structures of several derivatives prepared to test this view were left undetermined for future study. In the present study these have been determined in several cases and a number of other new halogenated derivatives prepared. These experiments have been conducted in the presence of aqueous alkali, a method which was in part standardized and designated in the previous work as the wet method. In the present work this process has been shown to be capable of two modifications, each with somewhat specific applications which can, in general, be predicted

Derivatives of 3-Amino-4-Methoxytoluene

This product, known technically as cresidine, was first obtained by Hofmann and Miller [Ber., 14, 573 (1881)]. Before the present work, however, only two substitution products had been obtained from it, viz., the 6-nitro and the 6-chloro derivatives. In this work a monobrom derivative has been prepared and its structure established. It readily forms a quaternary ammonium iodide, therefore the bromine atom does not occupy position 2, adjacent to the amino group, as this would hinder the formation of such a salt. 3-5-Dibrom-4-methoxytoluene was synthesized and found to be different from the dibrom derivative obtained from the compound in question by replacement of the amino group by bromine. This leaves the structure of the monobrom derivative as 3-amino- 4-methoxy-6-bromotoluene. The new bromine compound was characterized by the preparation of the following derivatives: 3-acetylamino-4-methoxy-6-bromotoluene, 3-benzoylamino-4-methoxy-6-bromotoluene (3-acetylamino-4-methoxy-6-bromobenzoic acid.

The Effects of Substituents on the Reactions of Certain Vanillin Derivatives

As far back as 1894 Victor Meyer (1) reported research on the effect of an ortho substituent influencing the reactivity of an active group. He observed among other things that methyl, chloride, bromide, or iodide substituents produced a steric hindrance effect roughly proportional to the molecular weight of the substituent. He also observed that the nitro group had an effect out of proportion to its weight, which indicated that its chemical nature also had a bearing. Cases have been reported in which the nitro group had an accelerating effect rather than a hindering one (2)

Oxidation of 4-Acyloxy Derivatives of Cinnamic Acid

It is known that benzaldehyde (17) and its alkyl, alkoxy and halogen substitution products are easily oxidized to the corresponding acids. In many cases contact with air brings about the change (4). The presence of hydroxyl as a substituent often makes the aldehyde less reactive toward oxidizing agents. For example, Bücking (3) and Fitting and Remsen (5) reported that p-hydroxybenzaldehyde and protocatechuic aldehyde, respectively, are not readily oxidized by potassium permanganate solution, but require fusion with caustic potash to give the related acids. Tiemann (13) found that when vanillin, the 3-methyl ether of protocateuchuic aldehyde, is treated with oxidizing agents hardly any change takes place or else complete decomposition occurs, depending on conditions, while Brady and Dunn (2) failed to oxidize 5-bromovanillin with acetic acid solution of chromic acid and also by alkaline solution of potassium permanganate

Modification of the Directive Influence of Substituents in Certain Benzene Derivatives

Bromination of vanillin, 3-methoxy-4-hydroxybenzaldehyde, gives a yield of 88-90 per cent of the 5-bromo compound which indicates that the chief directive influence is exerted by hydroxyl. If the hydroxyl radical is first acylated and the resulting acetyl or benzoyl vanillin is brominated, an equally high yield of the 6-bromo derivative is obtained, and no other product can be isolated. Vanillic acid and methyl vanillate likewise give good yields of the corresponding 5-bromo compounds, while the acylated derivatives give the 6-bromo substitution products only. These results indicate that acylation of hydroxyl suppresses its orienting effect and the entrance of bromine into position 6 shows that the methoxy radical then exercises the chief directive influence

The use of 2-Chlorophenoxyacetyl Chloride in the Preparation of Mixed Diacyl Derivatives of Ortho Aminophenols

Raiford and coworkers (1) have proved by a long series of experiments that when two acyl radicals, R-Ć=O and R\u27-Ć =O, are introduced into an ortho aminophenol only one mixed diacyl derivative can generally be obtained, regardless of the order of introduction of the radicals; and in this product the heavier and more acidic of these groups is usually found attached to nitrogen. To meet this requirement the migration of acyl from nitrogen to oxygen must occur in one of these reactions. If the acyls are R-Ć=O and R-0-Ć=O the latter is most frequently found on nitrogen

Benzenesulfinic Acid and Some of Its Derivatives

The migration of acyl from nitrogen to oxygen in o-aminophenol derivatives has previously been studied in this Laboratory.1 Rearrangement occurred with the acyls derived from carboxylic acids, but not with those obtained from sulfonic acids. It was therefore proposed to study the behavior of the sulfinyl radical in this connection

The Effect of Substituents in the Formation of Thiocarbanilides by Various Methods

A study of thiocarbanilide formation by four different methods has been made for the purpose of testing the effect of substituents in the amines used as starting materials. From a limited number of the thiocarbanilides guanidine derivatives were prepared by modification of the methods described by Marckwald (Ann., 286, 363 (1895)) and by Alway and Vail, (Am. Chem. J., 28, 158 (1902))

Identification of Hydrazones and Isomeric Pyrazolines Obtained from α, ß-Unsaturated Ketones

To date there are but two methods for distinguishing between these compounds. The first involves the reduction of the hydrazone with sodium amalgam to give aniline and the corresponding aliphatic amine. The yields are low and many cases tried have given negative results. The pyrazolines do not suffer this change. The second method is based on the fact that many of these hydrazones are rearranged by boiling acetic acid to the isomeric pyrazolines. If, in this way, the compound in question is converted into a new product, the latter is probably, but not certainly, a pyrazoline. If the latter can be oxidized to benzoic and a pyrazole acid, the pyrazoline is more clearly indicated