Chemical synthesis of a chiral oxazinone
AssigneeMerck Sharp & Dohme Corp.
InventorsRamon John Alabaster, Ian Frank Cottrell, Andrew William Gibson, Simon Adrian Johnson
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Abstract
The present invention provides a process for the preparation of substantially pure N-benzyl-3-(S)-(4-fluorophenyl)-1,4-oxazin-2-one which comprises: (i) contacting racemic N-benzyl-3-(4-fluorophenyl)-1,4-oxazin-2-one with (-)-3-bromocamphor-8-sulphonic acid (hereinafter referred to as (-)-3-BCS) in the presence of a racemising agent; (ii) collecting the resultant crystalline (-)-3-BCS salt of N-benzyl-3-(S)-(4-fluorophenyl)-1,4-oxazin-2-one; and (iii) liberating the free base of N-benzyl-3-(S)-(4-fluorophenyl)-1,4-oxazin-2-one by treatment of the (-)-3-BCS salt collected in step (ii) with aqueous base.
Claims11
A process for the preparation of substantially pure N-benzyl-3-(S)-(4-fluorophenyl)-1,4-oxazin-2-one which comprises:
- (i) contacting racemic N-benzyl-3-(4-fluorophenyl)-1,4-oxazin-2-one with (-)-3-bromocamphor-8-sulphonic acid (hereinafter referred to as (-)-3-BCS) in the presence of a racemising agent;
- (ii) collecting the resultant crystalline (-)-3-BCS salt of N-benzyl-3-(S)-(4-fluorophenyl)-1,4-oxazin-2-one;
- and
- (iii) liberating the free base of N-benzyl-3-(S)-(4-fluorophenyl)-1,4-oxazin-2-one by treatment of the (-)-3-BCS salt collected in step (ii) with aqueous base.
The compound N-benzyl-3-(S)-(4-fluorophenyl)-1,4-oxazin-2-one in the form of its 3-bromocamphor-8-sulphonic acid salt.
Dependencies are inferred from the claim text.