Zilpaterol hydrochloride in specific crystallized form, its prepn. process and intermediate products used

Anhydrous crystalline zilpaterol hydrochloride (I), contg. less than 5% of crystals smaller than 15 mu , the rest of the crystals being smaller than 250 mu , is new. Also claimed are (I)-monohydrate and (I)-trihydrate. The claimed prepn. of (I) comprises: (i) forming a super-satd. soln. of (I) in wa...

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Bibliographic Details
Main Authors YVES CHEVREMONT, JEAN-YVES GODARD
Format Patent
LanguageEnglish
Published 23.04.1997
Edition6
Subjects
CHEMISTRY
FODDER
FOODS OR FOODSTUFFS
HETEROCYCLIC COMPOUNDS
HUMAN NECESSITIES
HYGIENE
MEDICAL OR VETERINARY SCIENCE
METALLURGY
ORGANIC CHEMISTRY
PREPARATIONS FOR MEDICAL, DENTAL, OR TOILET PURPOSES
SPECIFIC THERAPEUTIC ACTIVITY OF CHEMICAL COMPOUNDS ORMEDICINAL PREPARATIONS
THEIR TREATMENT, NOT COVERED BY OTHER CLASSES
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Summary:Anhydrous crystalline zilpaterol hydrochloride (I), contg. less than 5% of crystals smaller than 15 mu , the rest of the crystals being smaller than 250 mu , is new. Also claimed are (I)-monohydrate and (I)-trihydrate. The claimed prepn. of (I) comprises: (i) forming a super-satd. soln. of (I) in water or in an ethanol/water mixt. at below 50 degrees C; (ii) cooling the soln. to crystallise the monohydrate; (iii) lowering the temp. to below 20 degrees C to crystallise the trihydrate; and (iv) drying to give the desired prod. A variation on the above procedure comprises dissolving (I) in water at below 30 degrees C to give a satd. aq. soln. from which the trihydrate recrystallises spontaneously. Alternatively, a soln. of (I) in a min. amt. of warm water (60-100 degrees C) is poured into a satd. soln. of (I) in a water/alcohol mixt. which has been previously stirred at below 20 degrees C and seeded with trihydrate, to give the trihydrate, which is then dried (all claimed).
Bibliography:Application Number: CN19961010424