Hydrazine hydrate (1:1) → (S,S)-2-hydroxycyclopentanecarboxylic Hydrazide

To a 50-mL four-necked flask were added 2.33 g (16.2 mmol) of methyl (S,S)-2-hydroxycyclopentanecarboxylate and 9.3 ml of 2-propanol and stirring was started. Hydrazine monohydrate (1.62 g; (32.3 mmol) was dropped thereinto at 23° C. taking 30 minutes. After the dropping, the mixture was stirred at 85° C. for 15 hours. Followed by, heating was stopped and the mixture was cooled down to room temperature to precipitate the crystals. The crystals were filtered and washed with a small amount of 2-propanol. The resulting crystals were dried to give 1.50 g of the title compound. The yield was 63%. Ratio of anti-form to syn-form of the compound was measured by the same manner as in Example 4 and found that the anti/syn ratio was more than 99/1.

1. addition(32.3 mmol) was dropped
2. stirringAfter the dropping, the mixture was stirred at 85° C. for 15 hours
3. temperatureFollowed by, heating
4. customto precipitate the crystals
5. filtrationThe crystals were filtered
6. washwashed with a small amount of 2-propanol
7. customThe resulting crystals were dried

ORD-Eintrag

ord-bfb117b0f2484137aa2b230ef9ee17e8

Quelldatensatz

uspto-grants-2006_05

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US07038087B2