May 6, 2013

CAS databases provide millions of journal article references from more than 10,000 major scientific journals worldwide, patent and patent family references from 63 patent authorities around the world, and other reputable web sources.

The following patent record is from the CAplusSM database.


Patent Number: US 8383857
Title: Method for the chemoselective preparation of hydrazides by acylation of a slurry of hydrazine in an inert solvent with an acid chloride at low temperature and its use in the preparation of 3-mercapto-3-methylbutanoic acid hydrazide
Inventor(s): Chiarello, George A.; Sahli, Ayman
Patent Assignee(s): Wyeth, John, and Brother Ltd., USA
Source: PCT Int. Appl., 49pp. CODEN: PIXXD2
Language: English

A method is disclosed for prepg. hydrazides from hydrazine and an acyl chloride by prepg. a stirred and substantially uniform slurry of hydrazine and an inert solvent at low temp. and then adding an acyl chloride continuously to said slurry; the modified method decreases the formation of the bis-hydrazide product present in the desired hydrazide.  The method is applied to the prepn. of 4-MeOC6H4CH2SCMe2CH2CONHNH2 (I) from the acid chloride 4-MeOC6H4CH2SCMe2CH2COCl (prepd. in two steps from 3,3-dimethylacrylic acid and 4-methoxybenzylthiol); I is converted to the thiol-contg. hydrazide HSCMe2CH2CONHNH2 (Cl-332258), used as a linker in the prepn. of immunoconjugates of monoclonal antibodies with calicheamicins.  The effects of temp., mixing speed, and reactor on the prepn. of I are detd.

Please note:  Abstracts and Titles for patent records in CAplus are routinely enhanced to better describe the claimed invention. The title of the U.S. granted patent is Processes for making hydrazides.

 View the full-text here.

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