Roxithromycin synthesis

Yield:-

Reaction Conditions:

with sodium ethanolate in acetone at 0 - 5; for 0.416667 h;

Steps:

A EXAMPLE A
Erythromycin-9-oxime (50 gm) was mixed with acetone (250ml), the mixture was stirred for 10 minutes, cooled to 0-5C. Sodium ethoxide (5.0 gm) was added followed by (methoxyethoxy) methyl chloride (8.6 ml), slowly with stirring, at 0-5C. The reaction was monitored by TLC until erythromycin-9-ioxime disappears. The reaction mixture was stirred at 0C to 5C for fifteen minutes and slowly raised up to ambient. Water (100 ml) was added to the reaction mixture and the reaction mixture became clear. Water (200ml) was added till turbidity appeared, when water addition was stopped. The reaction mixture was stirred for half an hour and other water (200ml) was added to the reaction mixture. After two hours the solid was filtered and washed with acetone: water (50:50) mixture, dried at 50-60C, to give crude roxithromycin (43.5gm)

References:

Alembic Limited EP1435359, 2004, A1 Location in patent:Page 5

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