Merck Sharp + Dohme Corp.

Merck Sharpe & Dohme Corp.

Peter G Houghton

Guy R Humphrey

Michael Stewart Ashwood

Stanley H Wright

Brian Cchristopher Bishop

A process for preparing tryptamine derivatives and related compounds having a 1,2,4-triazol-1-yl moiety within the molecule comprises reacting 4-amino-1,2,4-triazol with a nitrobenzene derivative containing a readily displaceable group; deaminating the aminotriazolium salt thereby obtained by treatment with nitrous acid followed by neutralisation; reducing the triazolyl-ni-trobenzene derivative thereby obtained by transfer hydrogenation; treating the triazolyl-aniline derivative thereby obtained with nitrous acid and then with an alkali metal sulphate, followed by acidification; and subsequently reacting the triazolyl-hydrazine derivative thereby obtained in situ with a suitable carbonyl compound, to obtain the required triazolyl-indole derivative.

Process for preparing indole derivatives containing a 1,2,4-triazol-1-yl

A process for preparing tryptamine derivatives and related compounds having a 1,2,4-triazol-1-yl moiety within the molecule comprises reacting 4-amino-1,2,4-triazol with a nitrobenzene derivative containing a readily displaceable group; deaminating the aminotriazolium salt thereby obtained by treatment with nitrous acid followed by neutralisation; reducing the triazolyl-nitrobenzene derivative thereby obtained by transfer hydrogenation; treating the triazolyl-aniline derivative thereby obtained with nitrous acid and then with an alkali metal sulphate, followed by acidification; and subsequently reacting the triazolyl-hydrazine derivative thereby obtained in situ with a suitable carbonyl compound, to obtain the required triazolyl-indole derivative.

A process for preparing a single enantiomer of a 4-aryloxyazetidin-2-one derivative in optically pure form comprises reacting a hindered vinyl ester with chlorosulphonyl isocyanate; displacing the hindered acyloxy group with a phenolic derivative containing a protected carboxy group; deprotecting the carboxylate moiety; resolving with a chiral amine; filtering; and regenerating the desired enantiomer by acidification. A method for enriching the product obtained from the acyloxy displacement step in favour of the desired enantiomeric form, by treating with an asymmetric catalyst such as a chiral alkaloid derivative, is provided; as also is a method for racemising the unwanted antipode of the desired 4-aryloxyazetidin-2-one enantiomer. The invention further provides novel enantiomers based on the 4-aryloxyazetidin-2-one ring structure.

Process for the preparation of chiral 4-aryloxyazetidinones

Compounds of formula III: ##STR1## wherein R.sup.1 is a 5- or 6-membered aromatic heterocyclic group; and R.sup.4 and R.sup.5 each idependently signify hydrogen, halogen, trifluoromethyl, cyano, nitro, amino or lower alkyl; are useful intermediates in a novel process for the preparation of a class of pharmacologically active compounds of formula I: ##STR2## wherein R.sup.1, R.sup.4 and R.sup.5 are as defined above; and R.sup.3 represents hydrogen or lower alkyl.

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Bassingbourn, United Kingdom

Peter G Houghton