Phosgene ammonia

Rea.ctlons, As with other tertiary alcohols, esterification with carboxyUc acids is difficult and esters are prepared with anhydrides (181), acid chlorides (182), or ketene (183). Carbamic esters may be prepared by treatment with an isocyanate (184) or with phosgene followed by ammonia or an amine (185). 

Ketone formation can also be avoided if one of the functional acyl halogens ia phosgene is blocked. Carbamyl chlorides, readily obtained by the reaction of phosgene with ammonia or amines, are suitable reagents for the preparation of amides ia direct Friedel-Crafts acylation of aromatics. The resulting amides can be hydroly2ed to the corresponding acids (134) ... 

Ammonia reacts vigorously with phosgene. The products are urea, biuret, ammeUde (a polymer of urea), cyanuric acid, and sometimes cyameUde (a polymer of cyanic acid). The secondary products probably arise through the very reactive intermediate carbamyl chloride [463-72-9] NH2COCI (see... 

Carbonyl sulfide reacts with chlorine forming phosgene (qv) and sulfur dichloride [10545-99-0] and with ammonia forming urea and ammonium sulfide [12135-76-1]. Carbonyl sulfide attacks metals, eg, copper, ia the presence of moisture and is thought to be iavolved ia atmospheric sulfur corrosion (27,28). Its presence ia propane gas at levels above a few ppm may cause the gas to fail the copper-corrosion test. 

FIG. 23-3 Temperature and composition profiles, a) Oxidation of SOp with intercooling and two cold shots, (h) Phosgene from GO and Gfi, activated carbon in 2-in tubes, water cooled, (c) Gumene from benzene and propylene, phosphoric acid on < uartz, with four quench zones, 260°G. (d) Mild thermal cracking of a heavy oil in a tubular furnace, hack pressure of 250 psig and sever heat fluxes, Btu/(fr-h), T in °F. (e) Vertical ammonia svi,ithesizer at 300 atm, with five cold shots and an internal exchanger. (/) Vertical methanol svi,ithesizer at 300 atm, Gr O -ZnO catalyst, with six cold shots totaling 10 to 20 percent of the fresh feed. To convert psi to kPa, multiply by 6.895 atm to kPa, multiply by 101.3. 

Phosgene [75-44-5] M 98.9, b 8.2 /756mm. Dried with Linde 4A molecular sieves, degassed and distilled under vacuum. This should be done in a closed system such as a vacuum line. HIGHLY TOXIC, should not be inhaled. If it is inhaled operator should lie still and made to breath ammonia vapour which reacts with phosgene to give urea. 

The Air Force Dispersion Assessment Model (ADAM -1980s) calculates the source term and dispersion of accidental releases of eight specific chemicals chlorine, fluorine, nitrogen tetroji ogen sulfide, hydrogen fluoride, sulfur dioxide, phosgene, and ammonia. It Ut a ... 

About 3 grams of 0-methylcholine chloride are stirred at room temperature with an excess of phosgene dissolved in 50 grams of chloroform, for about 2 hours. Excess phosgene and hydrochloric acid are removed by distillation under vacuo. Additional chloroform is added to the Syrup and the mixture is poured into excess ammonia dissolved in chloroform and cooled in solid carbon dioxide-acetone. The solid is filtered and extracted with hot absolute alcohol. The solid in the alcohol is precipitated with ether, filtered, and recrystallized from isopropanol. The carbaminoyl-0-methylcholine chloride obtained has a melting point of about 220°C. 

About 14 g of choline chloride are stirred with a solution of about 20 g of phosgene in 100 g of chloroform for about two hours at room temperature. The mixture becomes a two-phase liquid mixture. Hydrochloric acid and excess phosgene are removed by distillation in vacuo. Chloroform is added to the syrup, and the mixture is then added to a solution of excess ammonia in chloroform which was cooled with solid carbon dioxide-acetone. The mixture is... 

A solution of 34 cc (0.5 mol) of liquid phosgene in 150 cc of absolute ether is reacted while cooling with a mixture of sodium chloride and ice, first with 62 grams (0.5 mol) of 1-ethinyl cyclohexanoM and then with 64 cc (0.5 mol) of quinoline. The precipitated quinoline chlorohydrate is filtered off and the filtrate is reacted with ammonia in ether. 

A solution of 32 g (030 mol) phosgene in 200 ml benzene is added dropwise at 30°C to a stirred soiution of 53.5 g (032 mol) 3-o-toloxy-13-Pfopanediol in 400 ml benzene. The mixture is stirred for an hour after the addition is completed, and a solution of 39 g of dl-methylaniline in 100 ml benzene is then added, and stirring continued for a half-hour. Ice water (about one-third volume) is then added, and the benzene layer formed is separated and stirred with 500 ml concentrated ammonia at 5°Cfor six hours. The precipitated solid (weighing about 55 g) is recovered and recrystallized from water. The product thus obtained in a yield of about 53 g is 3-(o-toloxy)-2-hydroxypropyl carbamate it is a crystalline solid melting at about 93°C, and having a lower water-solubility and higher oil-solubility than 3-o-toloxy-13-propanediol. 

Carothers claimed that he kept going only because he finally received one of Illinois few scholarships, 750 embellished with esteem. But he must also have persevered because he loved chemistry. As he admitted, even the smell of his laboratory coat, saturated with the inexpressibly pungent and complicated odors of lab no. 219 [filled him] with a nostalgia to return to the atmosphere of sweetly blended sulfur dioxide, bromine, chlorine, ammonia, hydrogen chloride, phosgene, chloroacetone, etc., etc., etc. ... 

Research has shown that when polychlorpinen, ammonium nitrate, and superphosphate are present together in the soil, phosgene, carbon monoxide, nitric oxide, hydrochloric acid, ammonia, hydrocyanic anions, ozone, hydrogen fluoride and phosphide, etc. could appear in the air over the beet fields. Photooxidants could also appear. Airborne toxic compounds over this crop were noted in areas after precipitation with little wind, and with an air temperature of over 2CP . The combined and complex activity of pesticides and other chemical compounds led people who manually sowed beets to develop symptoms of poisoning. [21]... 

A fused heterocyclic compound (146) distantly related to the antiinflammatory agent cintazone (Chapter 12), which itself can be viewed as a cyclized derivative of phenylbutazone, retains the activity of the prototype, in the synthesis of 146, reaction of the nitroaniline 139 with phosgene gives intermediate 140, which is then reacted with ammonia to afford the substituted urea (141). Cyclization of the ortho nitrourea function by means of sodium hydroxide leads to the N-oxide (142) this last reaction represents... 

Toxic chemicals that are easy to be found in the industrial areas are chlorine, ammonia, hydrogen cyanide, formaldehyde, phosgene, hydrogen chloride. All of them are very harmful upon dispersal in the environment and would cause acute syndromes that require immediate qualified medical care. 

The replacement of both -OH groups with chlorine produces Ccirbonyl dichloride, also known as phosgene, a useful reactant. For example, phosgene reacts with two moles of alcohol to form a dialkyl carbonate. The reaction of phosgene with one mole of alcohol produces an alkyl chloroformate, which is a useful intermediate in organic syntheses. The reaction of phosgene with four moles of ammonia yields urea and two moles of ammonium chloride, NH Cl. Figure 12-40 shows the structures of some of these compounds. 

Ethinamate Ethinamate, 1-ethynylcyclohexanone carbamate (4.3.4), is synthesized by the condensation of acetylene with cyclohexanone and the subsequent transformation of the resnlting carbinol into carbamate by the subsequent reaction with phosgene, and later with ammonia [36,37]. 

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