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Process for the preparation of phosphorus-containing L-amino acids, their derivatives and intermediates for this process

  • US 5,442,088 A
  • Filed: 07/07/1994
  • Issued: 08/15/1995
  • Est. Priority Date: 04/06/1991
  • Status: Expired due to Term
First Claim
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1. A process for the preparation of a compound of the formula I or salt thereof, ##STR16## in which R1 and R2 independently of each other are hydrogen, (C1 -C6)-alkyl, which is unsubstituted or is mono- of polysubstituted by halogen or aryl, or (C3 -C10)-cycloalkyl,R3 and R4 independently of each other are hydrogen, (C1 -C6)-alkyl, (C2 -C6)-alkenyl, (C2 -C6)-alkynyl, where the last three radicals mentioned can be straight-chain or branched and can have hetero atoms in the chain, (C1 -C6)-alkylcarbonyl, aryl-(C1 -C4)-alkylcarbonyl, (C1 -C6)-alkoxycarbonyl, (C1 -C6)-alkylsulfonyl, benzyl, benzyloxycarbonyl, aryloxycarbonyl or arylsulfonyl, where the last four radicals mentioned are unsubstituted or substituted in the aryl radical,R5 is hydrogen or (C1 -C4)-alkyl, which is straight-chain or branched and is unsubstituted or substituted by halogen, aryl or a heterocycle, or (C3 -C7)-cycloalkyl andn is the number 0 or 1,which comprisesa) reacting an optically active S-homoserine lactone of the formula II, ##STR17## in which R3 and R4 are defined as in formula I, with hydrogen chloride in the presence of an alcohol of the formula R5 --OH to give a compound of the formula III ##STR18## in which R3, R4 and R5 are defined as in formula I, except that R5 =H, andb) reacting the resulting compound of formula III with a compound of formula IV,


  • space="preserve" listing-type="equation">R.sup.1 (O).sub.n -P(OR.sup.2).sub.2 (IV)
in whichR1, R2 and n are defined as in formula I and, if desired, hydrolyzing the product to give the compound of formula I, in which R5 =H.

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