With phenyl isocyanate

Anilides and a-Naphthalides. The Grignard reagents prepared from alkyl halides react with phenyl isocyanate (CgHjN=C=0) or with a-uaphthy l isocyanate (C,oH, N=C=0) to yield addition products that are converted by hydrolysis into anihdes and a-naphthalides respectively RX + Mg —> RMgX... 

Alcohols (but not ethers) also react with phenyl isocyanate or with the corre-sponding crystalline a-naphttiyl isocyanate to give carbamates or urethanes (see Section 111,27, ), but these substances are hardly suitable as class reagents. 

Sodium methanenitronate reacts with phenyl isocyanate in benzene to give the readily separable sodium salts of nitroacetaniUde and nitromalondiarkhde. Except as the salt, nitromethane is unreactive with phenyl isocyanate at temperatures up to 100°C the higher homologues do not give condensation products that can be isolated. 

The hydroxyl number can be deterrnined in a number of ways such as acetylation, phthalation, reaction with phenyl isocyanate, and ir and nmr methods. An imidazole-catalyzed phthalation has been used to measure the hydroxyl number for a number of commercial polyether polyols and compared (favorably) to ASTM D2849 (uncatalyzed phthalation) (99). The uncatalyzed method requires two hours at 98°C compared to 15 minutes at the same temperature. 

The acetyl content of cellulose acetate may be calculated by difference from the hydroxyl content, which is usually determined by carbanilation of the ester hydroxy groups in pyridine solvent with phenyl isocyanate [103-71-9J, followed by measurement of uv absorption of the combined carbanilate. Methods for determining cellulose ester hydroxyl content by near-infrared spectroscopy (111) and acid content by nmr spectroscopy (112) and pyrolysis gas chromatography (113) have been reported. 

Ethoxy-6-methylpyrimidine 1-oxide (499) reacts with phenyl isocyanate to eliminate carbon dioxide and give a mixture of 4-ethoxy-6-methyl-N-phenylpyrimidin-2-amine (SOO) and (the derived) 7V-(4-ethoxy-6-methylpyrimidin-2-yl)-7V,7V -diphenylurea (SOI) phenyl isothiocyanate reacts quite differently (79CPB2642). 

Substituted imidazoles can be acylated at the 2-position by acid chlorides in the presence of triethylamine. This reaction proceeds by proton loss on the (V-acylated intermediate (241). An analogous reaction with phenyl isocyanate gives (242), probably via a similar mechanism. Benzimidazoles react similarly, but pyrazoles do not (80AHC(27)24l) cf. Section 4.02.1.4.6). 

Enamines and enolate anions react with benzofuroxan to give quinoxaline di-A -oxides (Scheme 38) (69AHC(10)1). Sydnones (274) with phenyl isocyanate give 1,2,4-triazoles (275) (76AHC(19)l), and from (276) the intermediate adduct (277) can be isolated (73JA8452). This is one of the few instances in which such primary cycloadducts have been isolated in the oxazole series of mesoionic compounds. 

Aziridinones are also known to undergo cycloaddition reactions. Thus, treatment of (321) with phenyl isocyanate gave adducts (335) and (336) (76CL47). 

The i -toluanilide was prepared by the reaction of n-tolyl-magnesium bromide with phenyl isocyanate." If the ( -toluanilide has been recrystallized from petroleum ether, it may be necessary... 

Analogously to ynamines and o, /3-acetylenic ketones, 4-aminobut-3-yn-2-ones react with 1,3-dipoles (68HCA443 73HCA2427 92KGS867). The reaction of 4-dimethylaminobut-3-yn-2-one with diphenylketene follows a route of [2-1-21-cycloaddition (30°C, THF, 1 h) to give 2-acetyl-3-dimethylamino-4,4-diphenyl-cyclobut-2-en-l-one (377) in 15% yield. With ethyl azidoformate (30°C, THF, 3 h), the tiiazole 378 is formed in 82% yield, whereas with phenyl isocyanate, the quinoline 379 is the product (by a [2- -4] scheme) in 70% yield (68HCA443). 

For the characterization of 1,3-dialkyl-diaziridines, derivatives can be prepared with phenyl isocyanate. The reaction products (47) are... 

Trialkyl-diaziridines (e.g. 51) react with phenyl isocyanate with the same ease as the 1,3-dialkyl analogs. However, the compounds which result from the components in ratio 1 1 are not oxidizing agents and thus are not diaziridines. ... 

An interesting method of forming 2-oxo-3-phenyltetrahydro-l,3 oxazine (19) and its derivatives was recently given by Gulbins et at. It consists of heating a 2-oxo-l,3-dioxane with phenyl isocyanate ... 

Carbamates in some ways incorporate features of both esters and amides in the same function. Reaction of the piperidine bearing the diol side chain (88) with phenyl isocyanate affords the bis-carbamate. This product, diperodon (89) has found... 

It appeared that the impure alcohol isolated from balsam of Peru was, in fact, identical with nerolidol. When allowed to stand for three to four weeks with phenyl-isocyanate both alcohols yielded a phenyl-urethane, melting at 37" to 38°. A mixture of the two bodies suffered no depression in melting-point. The alcohols have the formula 15 260-The alcohol from balsam of Peru is therefore mixed with a small quantity -of an alcohol of higher specific gravity, the nature of which is still undetermined. Traces of benzyl alcohol were found in it, but not in sufficient quantity to account for the differences observed. Oxidation experiments did not throw any light on the question. It may therefore be safely assumed that the peruviol of Thoms consisted in the main of nerolidol, but contaminated with a substance of the same boiling-point to such an extent that its combustion figures pointed to the formula CjjH. jO instead of... 

It yields a phenylurethane if it is heated almost to boiliog-point with phenyl-isocyanate. This compound melts, at 106° to 107°. On dehydration with phosphoric acid it yields the sesquiterpene cedrene. The relationship between cedrene and cedrol is probably as follows —... 

Reaction of hydroxy groups with phenyl isocyanate and back titration of the excess isocyanate with dibutylamine. Both moisture and acidity interfere275. ... 

Several syntheses of annulated uracils of biological value were recently reported. The key reaction was a microwave-assisted one-pot [4 -i- 2] cycloaddition of oxazino[4,5-d]-, pyrano-[2,3-d]-, pyrido[2,3-dj- and pyrimido[4,5-djpyrimidines, in the sohd state [134] and under solvent-free conditions [135]. The synthetic approach was based on the reaction of NJ -di-methyl-5-formylbarbituric acid 208 with maleimide in the sohd state for 5 min under microwave irradiation at 120 °C to give the pyrano[2,3-d]pyrimi-dine derivative 209 in 90% yield (Scheme 76). The reaction of 208 with phenyl isocyanate under microwave irradiation in the absence of solvent... 

Methyl-3,4-dihydroquinazoline 72 <2000EJ02105> when treated with phenyl isocyanate resulted in the formation... 

Pyrazole iminophosphorane 620 reacts with phenyl isocyanate and several ArTADs in a three-component reaction to provide low yields of the corresponding heteroannulated pyrazoles 621 as the final products (Equation 93) <1994JOC3985>. 

Condensation of arylhyrazonooxomalononitrile with methyl isocyanate gave 286, which could be cyclized to iminotriazinecarbonitrile 287 (R = H). Its reaction with phenyl isocyanate gave 287 (R = CONHPh), which was cyclized by the action of triethylamine to give 288 (X = NH), which was in turn hydrolyzed to 288 (X = 0) (78HCA1175). 

Amino derivatives of 1,2,4-oxadiazoles, isoxazoles, and 1,2,5-oxadiazoles interact with phenyl isocyanate to produce various 3-substituted 5-amino-l,2,4-thiadiazoles, via intermediate thioureides which can be isolated. The tendency to rearrange follows the order 1,2,4-oxadiazoles, isoxazoles, and 1,2,5-oxadiazoles <1996CHEC-II(4)307>. 

Treatment of y-nitrothioamides 368 with phenyl isocyanate and triethylamine (nitrile oxide generation conditions) leads to a.j3-unsaturated nitriles 369. The mechanism proposed for this reaction is shown in Scheme 1.42, which includes the dehydration stage of the nitrile oxide formed (418). 

In a typical experiment the isocyanate (0.006 moles) was reacted with 1.5 g of the polysaccharide in 150 ml of a 5% LiCl/ N,N-dimethylacetamide solution at 90°C under nitrogen for two hours. The appearance of a strong infrared absorbance at 1705 cm l was an indication of carbamate formation. The derivatized polymer was isolated as a white powder by precipitation of the reaction solution into a nonsolvent such as methanol. Alternatively thin films were cast directly from solution the lithium salt could be removed by rinsing with acetone. Figure 1 illustrates the reaction of cellulose with phenyl isocyanate. 

Martins and Banks (1991) modified pine and wood samples with phenyl or butyl isocyanate and investigated the water vapour sorption properties of the modified wood. Modification resulted in a reduction in EMC at a given RH up to about 35 % WPG with butyl isocyanate, although reaction with phenyl isocyanate above 25 % WPG resulted in an increase in sorption due to cell wall damage caused by the reaction. The butyl derivative was more effective at reducing hygroscopicity over all the WPGs studied. 

Some recent work has made several heterocondensed furo[3,2-c]pyri-dines accessible. Starting compounds are the aldehydes of furo[3,2-c]pyri-dines, which are converted into the azides 203 (Scheme 75). Reaction with triphenylphosphane furnishes the iminophosphoranes 204, which are finally cyclized with phenyl isocyanate to afford the substituted pyrrolo[2, 3 4,5]-furo[3,2-c]pyridines 205 (92M807 94H1695). 

However, when pyridyliminophosphorane (306a) is treated with phenyl isocyanate or isothiocyanate (Scheme 110), mixed carbodiimides are obtained, which are capable of an intermolecular Diels-Alder reaction resulting in triazine 308. The cycloaddition occurs specifically with one C = N double bond of the carbodiimide serving as the dienophile (77ZC371). 

Phenyluracils with alkyl groups substituted in the 5- and 6-positions, such as (L), are reported to have analgesic and antipyretic activity [376, 377]. The 1-position may also be alkylated. Such compounds are prepared by the treatment of a-alkyl-/3-aminocrotonates with phenyl isocyanate. When the 5-substituent is an isopropyl group, the resulting compound is a sodiuretic without increase in potassium excretion. 

Carboxy substituted diazepines 226 and 229 react with phenyl isocyanate to afford pyrimido diones 227 and 230, correspondingly (Scheme 48, Section 3.1.1.3 (1993JHC897)). N-Hydroxymethylation on an indole ring annulated to benzaze-pinone, as well as formation of the corresponding carbamate and urea, has been described (2004MI1076). 

---