Products Obtained

When sugars are treated with aqueous ammonia for a short time at low temperature in the absence of a catalyst, the reaction is arrested before heterocyclic compounds can be formed in appreciable proportion, and the products are mainly epimerization products of the sugars, probably formed by way of their 2,3-enediols. These epimerization products are summarized in Table I which shows the reactions of D-glucose, D-fructose, lactose, maltose, and melibiose with aqueous ammonia for a short time at low temperature. A dark-colored, high polymer is also formed in some instances (the browning reaction). In the ammoniacal solution, the monosaccharides are epimerized the disaccharides are epimerized and, in addition, may be hydrolyzed to monosaccharides that can also be epimerized hence, the variety of products obtained may be considerable. 

Compounds Isolated from the Reaction of Free Sugars with Aqueous Ammonia 

51 Me R,. R H 2-methyl-5-(D-arafcino-tetrahydroxy- butyl)-3-(D-er5/tIiro-trihydroxypropyl) 

Reaction of Ammonia with Various Sugars at Low Temperature (Long Reaction Time with No Catalyst) 

At elevated temperatures, sugars react more quickly than at lower temperatures with aqueous ammonia, to give, mainly, substituted imidazoles and pyrazines, summarized in Table IV, and a catalyst is not needed. At the higher temperatures, there is an increase in the methyl-pyrazine and -imidazole fractions and a decrease in the (hydroxymethyl)imidazole and (tetrahydroxybutyl)pyrazine fractions, indicating occurrence of thermal cleavage of the side chains.10 

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Table 5.15 gives some physical-chemical characteristics of selected main refinery streams capable of being added to the diesel fuel pool. Also shown is the weight per cent yield corresponding to each stock, that is, the quantity of product obtained from the feedstock. 

The hydrogen product obtained has a purity between 97 and 99.9 volume %. The balance is methane, and the by-product of the process is CO2. 

Table 5 xlassification in terms of decreasing sensitivity performances of fluorescent product obtained on the nickel-chromium specimens of 20 et 10 pm... 

Table 6 classification in terms of decreasing sensitivity performances of coloured products obtained on the Nickel-chromium specimens of 50 et 30 pm Tests realized on nickel-chomium specimens of 20pm with coloured products don t change the classification. 

Concentrated sulphuric acid and nitric acid—powerful oxidising agents—attack all the elements except nitrogen, particularly when the acids are warm. The products obtained reflect changes in stability of the oxidation states V and III of the Group V elements. 

Addition of water gives the hydrated nitrate Cu(N03)2.3H2O, the product obtained when copper (or the +2 oxide or carbonate) is dissolved in nitric acid. Attempts to dehydrate the hydrated nitrate, for example by gently heating in vacuo, yield a basic nitrate, not the anhydrous salt. 

Saccharic acid. Use the filtrate A) from the above oxidation of lactose or, alternatively, employ the product obtained by evaporating 10 g. of glucose with 100 ml. of nitric acid, sp. gr. 1 15, until a syrupy residue remains and then dissolving in 30 ml. of water. Exactly neutralise at the boiling point with a concentrated solution of potassium carbonate, acidify with acetic acid, and concentrate again to a thick syrup. Upon the addition of 50 per cent, acetic acid, acid potassium saccharate sepa rates out. Filter at the pump and recrystaUise from a small quantity of hot water to remove the attendant oxahc acid. It is necessary to isolate the saccharic acid as the acid potassium salt since the acid is very soluble in water. The purity may be confirmed by conversion into the silver salt (Section 111,103) and determination of the silver content by ignition. 

Undecylenic acid (or 10-undecenoic acid) (I), a comparatively inexpensive commercial product obtained from castor oil, reacts with bromine in dry carbon tetrachloride to give 10 11-dibromoundecoic acid (II), which upon heating with a concentrated solution of potassium hydroxide yields 10-niidecynoic acid (III) ... 

S e Section I1.50,S. The commercial product, obtained soon after its preparation from the manufacturers, is satisfiEictory. 

Structure determination of the products obtained by alkylation was established previously by ... 

Scheme 55) (235. 236). -The product obtained (77) is probably formed via the protonated form of the thiazole, whose reactivity is treated in Section IV, 1. The light-yellow leucobase (77) is reported to be oxidized by PbOj to the red-black carbinol (78) (236). This condensation reaction is also successful when benzaidehyde is replaced by formaldehyde, bis(2-amino-4-phenylthiazolyl-5)methane (79 i beine obtained (Scheme 56) (237). 

Alkylation of 2-methylaminothiazole (204) with ROH in 85% sulfuric acid gives 2-methylimino-3-alkyl-4-thiazoIine (54). 2-Amino-4-rnethyl-thiazoie alkylated with an excess of isopropanol, however, gives 95% of 2-isopropylamino-4-methyl-5-isopropylthiazole (56). The same result is obtained with cyclohexanol (242). These results and those reported in Sections III.l.C and IV.l.E offer interesting new synthetic possibilities in thiazole chemistry. The reactive species in these alkylations is the conjugate acid of 2-aminothiazole. and the diversity of the products obtained suggests that three nucleophilic centers may be operative in this species. 

Rumpf et al. (97) studied the ultraviolet spectra of products obtained when 2-amino-4 phenylthiazole is acylated by /3-chloropropionyl chloride and y-chlorobutyrylchloride and showed that their structures were 94 and 95, respectively (Scheme 66). The open-chain intermediate to 95, 2-(3-... 

The sodium salt of X -2-thiazolyl dithiocarbamic acid (141) is obtained by reaction in NaOH between 2-aminothiazole and CSj (Scheme 93) (305). The product obtained in neutral medium is described as the... 

Diazo coupling involves the N exocyclic atom of the diazonium salt, which acts as an electrophilic center. The diazonium salts of thiazoles couple with a-naphthol (605). 2-nitroresorcinol (606), pyrocatechol (607-609), 2.6-dihydroxy 4-methyl-5-cyanopyridine (610). and other heteroaromatic compounds (404. 611) (Scheme 188). The rates of coupling between 2-diazothicizolium salts and 2-naphthol-3.6-disulfonic acid were measured spectrophotometrically and found to be slower than that of 2-diazopyridinium salts but faster than that of benzene diazonium salts (561 i. The bis-diazonium salt of bis(2-amino-4-methylthiazole) couples with /3-naphthol to give 333 (Scheme 189) (612). The products obtained from the diazo coupling are usuallv highly colored (234. 338. 339. 613-616). 

In the reaction of 4-substituted 2-aminoselenazoles with ethyl propiolate and dimethylacetylene dicarboxylate. the major products obtained from such a condensation are substituted 7H-selenazolo[3,2-a]pyrimidin-7-ones (5) and not the alternative isomeric substituted 5H-selenazoles[3,2-a]pyrimidin-5-ones (6). Distinction between the alternative structures was based on infrared, ultraviolet, and NMR data (Scheme... 

Substrates Reaction time (hr) Substitution (%) Methylated product obtained (total lOOSl... 

Reaction of various reagents (CH3I. CjHjI, PhCHO) on the organolithium products obtained by reaction of butyl-lithium with 2-methyl-4-phenylthiazole gives approximately 90% 5-substitution. The increased reactivity of the hydrogen in the 5-position can be explained by the fact that the -r J effect of a 4-methyl group would increase the electron... 

In practice hydrogenation of a pinene is observed to be 100% stereoselective The only product obtained is cis pinane No trans pinane is formed... 

Write the structure of the major organic product obtained by... 

The first breakthrough came m 1911 when Richard Willstatter prepared cyclooc tatetraene by a lengthy degradation of pseudopelletienne a natural product obtained from the bark of the pomegranate tree Today cyclooctatetraene is prepared from acetylene m a reaction catalyzed by nickel cyanide... 

Write the structure of the principal organic product obtained on nitration of each of the following... 

The syn stereochemistry of dibromocarbene cycloaddition was demonstrated in experiments using as- and trans-2 butene Give the structure of the product obtained from addition of dibromocarbene to each alkene... 

Give the structure of the product obtained when ethyl phenyl acetat C6H CH2C02CH2CH3) is treated with each of the following esters under conditions of the mixed Claisen condensation... 

Thiourea (H2NCNH2) reacts with diethyl malonate and its alkyl derivatives in the same way that urea does Give the structure of the product obtained when thiourea is used instead of urea in the synthesis of pentobarbital The anesthetic thiopental (Pentothal) sodium is the sodium salt of this product yWhat IS the structure of this compound ... 

Gngnard reagent is consumed but the only organic product obtained after working up the reaction mixture is ethyl acetoacetate Why" What happens to the Gngnard reagent" ... 

Another interesting structure with a high degree of ring character along the backbone is the product obtained by the reaction of 1,4-cyclohexanedione [XIV] and pentaerythritol [XV] ... 

Hydrogenation of the aromatic ring to form naphthenic compounds has been proposed as a route to faciUtate the separation of the Cg aromatic isomers (31). The spread in boiling points of the naphthenic compounds is 12°C vs a spread of 8°C for the aromatic compounds. However, the cycloparaffinic products obtained from OX and EB boil only 3°C apart, impeding the separation. 

If ah of the nonfiltration operations are grouped together into a downtime, assumed to be fixed and known, an optimum filtration time in relation to p can be derived by optimizing the average dry cake production obtained from the cycle. Eor constant pressure filtration and where the medium resistance R and the specific cake resistance are constant, the fohowing equation appHes ... 

Table 11 presents data on the protein quaUty of a variety of LPC products obtained from rat-feeding studies. Typical protein efficiency ratio (PER) values for LPCs derived from alfalfa range from 1.41 without supplementation to 2.57 with 0.4% methionine added casein can be adjusted to a PER of 2.50 (98,100). Biological values (BV) of mixtures of LPCs, such as barley and rye grass or soybean and alfalfa, maybe higher than either LPC alone. The effect has been attributed to the enhanced biological availabihty of lysine in these mixtures (99). 

History. Methods for the fractionation of plasma were developed as a contribution to the U.S. war effort in the 1940s (2). Following pubHcation of a seminal treatise on the physical chemistry of proteins (3), a research group was estabUshed which was subsequendy commissioned to develop a blood volume expander for the treatment of military casualties. Process methods were developed for the preparation of a stable, physiologically acceptable solution of alburnin [103218-45-7] the principal osmotic protein in blood. Eady preparations, derived from equine and bovine plasma, caused allergic reactions when tested in humans and were replaced by products obtained from human plasma (4). Process studies were stiU being carried out in the pilot-plant laboratory at Harvard in December 1941 when the small supply of experimental product was mshed to Hawaii to treat casualties at the U.S. naval base at Pead Harbor. On January 5, 1942 the decision was made to embark on large-scale manufacture at a number of U.S. pharmaceutical plants (4,5). 

Sulfonation of aromatic hydrocarbons with sulfuric acid is cataly2ed by hydrogen fluoride or, at lower temperatures, by boron trifluoride (144). The products obtained are more uniform and considerably less sulfuric acid is needed, probably because BF forms complexes with the water formed ia the reaction, and thus prevents dilution of the sulfuric acid. 

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