Carbamoyl chlorides, chlorination

Effect of Hydrolyzable Chlorine on Activity of Tin Catalysts. The effect of small amounts of hydrolyzable chlorine on the catalytic activity of DBTDL was studied on the model aliphatic system—isocy-anatoethyl methacrylate and n-butanol. The presence of the hydrolyzable chlorine in isocyanate usually decreases the reactivity of isocyanates in the urethane reaction. The results of measurements of the chlorine effect on the change of the rate constant is summarized in Figure 8. It was determined that the very small amounts of the hydrolyzable chlorine, especially in the form of carbamoyl chloride, increased at the beginning the rate constant for the urethane reaction catalyzed by DBTDL and after achieving the maximum at 500 ppm of chlorine the reactivity decreased. This effect was not observed when benzoyl chloride was used in place of carbamoyl chloride. It was assumed that the activation effect of the chlorine was due to the interaction of the carbamoyl chloride with the DBTDL catalyst. In order to understand this effect, the interaction of DBTDL with carbamoyl chloride of hexamethylene diisocyanate (with and without the presence of n-butanol) was studied using the IR technique. Results are summarized in Figure 9. 

The reaction of isocyanates with phosphorus pentachloride, and the reaction of secondary carbamoyl chlorides with chlorine, yield carbonimidoyl dichlorides. Gumpert in 1885 investigated the reaction of phenyl... 

In addition to isocyanates secondary carbamoyl chlorides are readily converted to carbonimidoyl dichlorides by high-temperature chlorination, provided one of the alkyl substituents is a methyl group (31.49-52,54 ... 

Thus, chloromethylcarbonimidoyl dichloride (XXX) can be obtained by the chlorination of either N,N-bis(chloromethyl)carbamoyl chloride (XXXI) or N,N-dimethylcarbamoyl chloride (XXXII) at 190-200 C. Upon further chlorination dichloromethyl- (XXXIII) and trichloromethylcarbon-imidoyl dichloride (XXXIV) are obtained (31.49-54,99)... 

However, the reaction proceeds preferentially via route (a), as evidenced by the isolation of 72 % of the tetrameric cyanogen chloride XXXVIII. The triazine derivative XXXVIII can also be obtained by chlorination of the corresponding isothiocyanate C% A somewhat lower yield of the triazinyl-bis-carbonimidoyl chloride was obtained in the chlorination of 2,6-bis(di-methylamino)-4-chloro-l,3,5-triazine ( ). If cyclic carbamoyl chlorides, or carbamoyl chlorides having alkyl substituents other than methyl are chlorinated, the expected imidoyl chlorides are obtained For... 

The chlorination of certain cyclic amines and carbamoyl chlorides affords imidoyl chlorides ( ) however, this method is of only limited synthetic value. 

Perhalogenated imidoyl chlorides are also obtained by the direct high-temperature chlorination of carbamoyl chlorides. For example, chlorination of morpholine N-carbonyl chloride (LIII) at 200°C yields the perchloro derivative LIV ( ). 

The formation of acid halides from an alkyl halide and carbon monoxide in the presence of a Group VIII metal compound is a known process [130]. By analogy, an alternative procedure for preparing carbamoyl chloride by the insertion of carbon monoxide into the nitrogen-chlorine bond has been reported [131]. 

In analogy to the conversion of carboxylic acids to acyl chlorides, it has been found that carbamic add derivatives 216 can be converted to carbamoyl chlorides 218 by chlorination with an electrophilic agent such as thionyl chloride 217 or POCI3... 

Cyanuric chloride on monosubstitution with nucleophiles such as methanol or 4-amino-azobenzene followed by displacement of a second chlorine with alanine amide gave compounds which are used for precolumn derivatization of amino acids. The diastereoisomers formed are resolved by reverse-phase HPLC <92MI 6l2-0i>. Enantiomeric amino acids are separated by HPLC on bis[carbamoyl(alkyl)methylamino]-6-chloro-l,3,5-triazine derived stationary phases <93JC277>. 

Functionalized dichloromethylsulfenyl chlorides (XC12CSC1) will clearly give rise to 5-substituted analogs a-carbamoyl-a,a-dichlorosulfenyl chlorides (165), for example, which have become available by chlorination (S02C12)... 

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