BUY EASTMAN ORGANIC CHEMICALS Backed b y r e l i a b l e house. Locally stocked b y l a b sup pliers. Reagents a n d solvents of e v e r y v a r i e t y . O t h e r organic
compounds
f o r which
purchasers
constantly
find new uses. W a s t e s time to make w h a t y o u can b u y unless need exercise. Send f o r f r e e c a t a l o g N o . 4 2 to Distillation Products Industries, Rochester 3 , Ν . Υ. List ings
b y functional
groups
also supplied
gratis on
request.
Above is the basic message. Oh, there are details that can be rivatives. Since such reagents are few and far between, you may even wish to send for a procedural abstract. Or for an spun out . . . employment application form. Reagent fo identify a l k y l halides Eastman 8164 Methyl Fluorene-9-carboxylate 5 grams $5.00 A holding jig for a m i n o acids Eastman 7819 p-Nitrobenzyl Chloroformate 5 grams $3.30 For many years we have been hiring chemistry graduate students for summer jobs. It gives them a chance to look us over and For about 30 years, when chemists in their crude way have vice versa. Some of the biggest wheels in the corporation came tried to couple amino acids together, they have used a "carbothat way. Others found three months of estival service to benzoxy" group (CeHsŒhOCO-) to cap off the amino group of mammon sufficient for a lifetime and have become famous pro one amino acid while preparing the carboxyl end of the acid for fessors of chemistry. Still others have slipped through our the coupling reaction. These "carbobenzoxy" derivatives of fingers to become wheels in other companies. (You can't win amino acids are oily things. More recently (J.A.C.S., 74, 3818 [1952] ) it has been found that with a nitro group in them all.) This compound represents a week's work last summer by one p- position on the ring you get stable crystalline derivatives inof these young men. The man he was hired to assist specializes stead of oil. It is time to make known that Eastman 7819 is the in organometallic reactions. The mentor found a lithium reac proper nitro reagent. p-Nitrobenzyloxycarbonyl derivatives of tion to give him (from the April 1960 Analytical Chemistry on the 19 common amino acids can be prepared. (Because of the page 554). The summer man reacted lithium wire with bromo- nitro group these derivatives can be detected in very small benzene to produce phenyllithium. He used this to replace one amounts by spectrophotometry at 265ιτιμ.) In the presence of a base to take up the HCI released, you of the central hydrogens in ^ \ , / ^ by lithium. condense the reagent with your amino acid. Then you can con vert the product to an acid chloride and react it with the methyl ester of another amino acid. Saponify the resulting ester and fluorene remove the carbo-p-nitrobenzyloxy group by hydrolysis. Bench ! chemistry is crude indeed by comparison with cell chemistry. Next, ! ' + C02->Nevertheless, the reagent is selling rather well. We make it by '\ C / Vv" reacting pure p-nitrobenzyl alcohol with phosgene in dioxane X H Ai v/ AoOLi as solvent. Whether we have ever lost any production through On acidification, an Η replaced the the splitting off of CO2 from the product to leave nothing but Li. He then esterified with methanol, p-nitrobenzyl chloride, we are not saying. with HCI as catalyst. His product, ^ACA·* For the carriage trade COOCH3 Eastman 2313 Benzenesulfonic Acid 500 grams $14.25 was good enough to overcome the skepticism of our genial but Until now we have always felt constrained to put a " P " for skeptical chief control chemist. Nobody patted him on the head for his accomplishment. All Practical or a " T " for Technical in front of "2313." Now there he accomplished was to make it unnecessary for other chemists is a prefixless Eastman Grade. Worst metal contaminant left who look up the Anal. Chem. reference to spend a week of their is Fe at 0.3 p.p.m. Used to be that nobody felt that deeply about own time preparing the reagent that has been found to react purity in benzenesulfonic acid, but with the generally rising with a wide variety of alkyl halides to yield sharp-melting de taste for luxury there are now some who do. Prices are subject to change without
there a r e some
3800
notice.
Eastman Organic Chemicals
Distillation Products Industriesisa division of Eastman Kodak Company VOL.
33, NO. 4 , APRIL 1961
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