Isocyanato acid chloride

The isocyanato acid chloride 291 (X = CH2CH2, CH = CH), prepared through trimethylsilyl esters (Section II,A,4), reacts with aniline to give the isocyanato carboxamide 292, which readily yields the quinazolinedione 293 (73AG86 75LA1387). Armarego has prepared the quinazolindiones... 

Another interesting application of iminium chlorides in organic synthesis involves their use as catalysts in the conversion of carboxylic acids to carboxylic acid chlorides ( ), carbamates to isocyanates ( ), amino-acids to isocyanato acid chlorides and arylamine hydrochlorides to isocyanates In these reactions chlorodimethylformiminium chloride is being used, because it is readily available. However, other imidoyl halides could react in a like manner. 

The reactions of amino acids or amino alcohols with phosgene are interesting since they provide in one step molecules with two different functional groups, namely isocyanato acid chlorides or isocyanato chloroformates. 

A procedure using trichloromethyl chloroformate (diphosgene) has been successfully applied in the synthesis of isocyanato acid chlorides and isocyanato chloroformates from amino acids and amino alcohols, respectively [161,1016]. 

All of the synthesized compounds described thus far in this chapter have been of monovalent reactivity, i.e. the compounds consist of one or more active functional groups of the same selectivity and, where appropriate, one or more further non-active functions. Difunctional compounds such as isocyanato-chloroformate 108 [60] (Section 4.2.1), 446 [300] (Section 4.3.1.4), isocyanato-carbamoyl chloride 179 [111, 112] (Section 4.2.2.2), isocyanato acid chloride 1231 [447] (Section 4.3.5.4), and 1343 [1016] (Section 4.4.2.3), also fall into this category because all of their functions are of the same selectivity, in these examples electrophiles. 

Iron tricarbonyl dieme complex, 57, 16 Isobutyl chloroform.ate, 59, 165 Isobutylene, 59, 164 Isobutyl fluoride, 5, 73 Isobutyryl chloride, 59, 29 Isocyanato acid chlotrides, from amino acids, 59, 200... 

Trichloromethyl chloroformate has proven effective in the preparation of N-carboxy-a-amino acid anhydrides from amino acids, and various compounds having isocyanate, acid chloride, and chloroformate groups.For example, trichloromethyl chloroformate may be used instead of phosgene in the preparation of 2-tert-butoxycarbonyloxyimino-2-phenylacetonitrile. The use of this reagent is illustrated here by the synthesis of 3-isocyanato-propanoyl chloride from 3-aminopropanoic acid hydrochloride. 

Isocyanato- and 2-isothiocyanatobenzonitriles 1 react with hydrogen halides in dibutyl ether to give 4-haloquinazolin-2(li/)-ones and -quinazoline-2(l//)-thiones 2, respectively. The ring closure is based on a nucleophilic attack of the intermediary nitrile-halide adducts at the carbamic or thiocarbamic acid chloride function. 

Carboxy includes carboxy (carboxylic acids), alkoxycarbonyl (esters), carbamoyl (amides), thiocarbamoyl, hydrazinocarbamoyl (hydrazides), guanidinocarbonyl, azidocarbonyl (azides), chlorocarbonyl (acid chlorides), amidino, C-hydrazino-C-iminomethyl, C-alkoxy-C-iminomethyl (imino ethers), C-alkylthio-C-iminomethyl (iminothioethers), cyano (nitriles), C-formyl(aldehydes), dialkoxymethyl (acetals of aldehydes), C-acyl (ketones), isocyanato, and thiocyanato groups. 

The phosgenation of isatoic anhydride and aminocarboxylic and amino-sulfonic acids, to afford isocyanatoarylcarbonyl chlorides and isocyanato-arlsylfonyl chlorides, is also catalyzed by iminium chlorides. 

The reaction of >-isocyanato carboxylic acid chlorides with ethyl carbamate, in the presence of zinc chloride, affords ft>-isocyanatoalkyl carbamates 260 . 

Isocyanic acid, 2-(chIoroformyl)ethyl ester (8) Propanoyl chloride, 3-isocyanato- (9) (3729-19-9)... 

Benzene carboxaldehyde. See Benzaldehyde Benzenecarboximidamide, 4,4 -[1,6-hexanediylbis (oxy) bis-. See Hexamidine Benzenecarboxylic acid. See Benzoic acid Benzene chloramine. See Chloramine-B Benzene chloride. See Chlorobenzene Benzene, 1-chloro-2-isocyanato-. See2-Chlorophenyl isocyanate Benzene, 1-chloro-3-isocyanato-. See3-Chlorophenyl isocyanate Benzene, 1-chloro-4-isocyanato-. See4-Chlorophenyl isocyanate Benzene, 2-chloro-4-isocyanato-1-methyl-. See 3-Chloro-4-methylphenyl isocyanate Benzene, (chloromercuho)-. See Phenylmercuric chloride Benzene, chloromethyl-. See Monochlorotoluene... 

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