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Process for the N-alkylation or ureas

  • US 5,124,451 A
  • Filed: 07/10/1991
  • Issued: 06/23/1992
  • Est. Priority Date: 08/14/1990
  • Status: Expired due to Fees
First Claim
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1. Process for the preparation of ureas of the formula ##STR4## in which R1 and R2 independently of one another denote hydrogen, a linear, branched or cyclic alkyl group which is unsubstituted or substituted by groups inert under the conditions of the reaction, or an aralkyl group, or R1 and R2, together with the nitrogen atom, denote a non-aromatic, heterocyclic ring and R3 denotes an alkyl group which is unsubstituted or substituted by groups inert under the conditions of the reaction, the tertiary butyl group being excluded, comprising N-alkylating a urea of the formula ##STR5## in which R1 and R2 have the abovementioned meaning in the presence of a solid base and in the presence of a phase transfer catalyst in a diluent at temperature of 0°

  • to 150°

    C. with an alkylating agent of the formula
    
    
    space="preserve" listing-type="equation">(R.sub.3).sub.n -X IIIin which R3 has the meaning indicated above and n denotes the numbers 1 or 2, X representing a sulfonic acid or bisulfate group in the event that n denotes the number 1, and X representing a sulfate group in the event than n denotes the number 2.

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