Abbott Laboratories Corporation

Richard R Copp, Jr

John E Hengeveld

Ramiya H Premchandran

Philip E Bauer

Ashok K Gupta

David B Murphey

Rodney M Mittag

Kimberly Ann Allen

Brian T Fohey

Greg S Lannoye

Xiaoxing Dong

Dennis M Abad

Brian S Moon

Elise H Leese

The present invention provides a simple, 1-step process for preparing a N-(aryl or heteroaryl)-hydroxyurea comprising reacting the corresponding alcohol, ester or ether with hydroxyurea and acid. This reaction is particularly useful for preparing a benzo[b]thienyl substituted N-hydroxyurea of formula: ##STR1## from compound 1: ##STR2## by reacting compound 1 with hydroxyurea and acid. R.sup.1 is selected from the group consisting of hydrogen, 1-6 carbon alkyl, 1-6 carbon alkoxy, and halogen; R.sup.2 is an 1-4 carbon alkyl; and R.sup.3 is selected from the group consisting of hydrogen, acyl, methyl, ethyl and mixtures thereof. Additional steps to isolate the pure bulk product follow.

Synthesis and isolation of N-(aryl or heteroaryl)-alkyl-N-hydroxyurea

Disclosed is an improved and efficient process for N-desmethylating the 3'-amino nitrogen of erythromycins and for converting the 3'-N-desmethylated erythromycins into 3'-N-substituted derivatives of 8,9-anhydro-erythromycin 6,9-hemiketals.

Process for N-desmethylating erythromycins and derivatives thereof

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Kenosha, WI, United States of America

Richard R Copp, Jr