Xyzal

Trade names Vozet Xozal Xusal Xyzal (UCB Pharma) Indications Allergic rhinitis, chronic idiopathic urticaria Category Antihistamine Half-life 6-10 Hours 

Laroscorbine ascorbic acid levocetirizine Vozet, Xozal, Xusal, Xyzal 

Omeprazole (Losec) Bupivacaine (Sensorcaine) Ketoprofen (Orudis) Ofloxacin (Floxin) Cetirizine.HCl (Zyrtec) AstraZeneca AstraZeneca Wyeth Ortho-McNeil Pfizer Esomeprazole (Nexium) Levobupivacaine (Chirocaine) Dexketoprofen (Enantyum) Levofloxacin (Levaquine) Levocetirizine (Xyzal) AstraZeneca Chirosdence Menarini Ortho-McNeil Sepracor 

The antihistamine dmg cetirizine, which is a piperazine derivative, is a racemic mixture, and has been used in the treatment of rhinitis and hay fever. It is available over the counter as the well-known ZYRTEC (McNeil-PPC, Inc). However the levo-rotatory R-enantiomer (10.29) was later found to be the more active form and is now on the market as the prescription dmg XYZAL (Sanofi-Aventis U.S. LLC). An approach for the synthesis of the enantiomers of cetirizine is expressed by Scheme 10.11, wherein chiralty in the dmg is introduced at an early stage in the synthesis. Thus, compound 10.28 was synthesized in racemic form then converted into diastereoisomeric salts with an optically active tartaric acid. To procure the (—)-enantiomer of 10.28, the resolution was performed with (-l-)-tartaric acid for the (-l-)-enantiomer, the resolution employed (—)-tartaric acid. After separation of the salts by crystallization, the 10.28 enantiomers were released by treatment with base and each then converted to optically active cetirizine enantiomers or related compounds by use of the general reaction suggested by Scheme 10.11 for the synthesis of the (R)-isomer of cetirizine. 

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