Hydrazine hydrate (1:1) → 1,1-Dimethylethyl 3a,4,6,6a-tetrahydro-6a-hydroxypyrrolo[3,4-c]pyrazole-5(1H)-carboxylate

HRID 340755Notes

Reaction equation

C[N:2](/[CH:4]=[C:5]1/[CH2:6][N:7]([C:11]([O:13][C:14]([CH3:17])([CH3:16])[CH3:15])=[O:12])[CH2:8][C:9]/1=[O:10])C.O.[NH2:19]N>C1(C)C=CC=CC=1>[OH:10][C:9]12[CH2:8][N:7]([C:11]([O:13][C:14]([CH3:17])([CH3:16])[CH3:15])=[O:12])[CH2:6][CH:5]1[CH:4]=[N:2][NH:19]2

Participants

Conditions

Temperature: 5 °C

Procedure

To a solution of tert-butyl (3Z)-3-[(dimethylamino)methylene]-4-oxopyrrolidine-1-carboxylate (58.2 kg, 242 mol) in toluene (251 kg) at 35-45° C. was added hydrazine hydrate (14.6 kg, 290 mol) via drop-wise addition over 2 h. The mixture was then stirred for 10 h at this temperature. The batch was then cooled to 0-10° C. and the slurry stirred for 6 h. This slurry was then filtered and the cake washed with n-heptane. The solids were then dried under vacuum overnight at 35-50° C. to give tert-butyl 6a-hydroxy-3a,4,6,6a-tetrahydropyrrol[3,4-c]pyrazole-5(1H)-carboxylate.

Workup

additionvia drop-wise addition over 2 h
stirringthe slurry stirred for 6 h
filtrationThis slurry was then filtered
washthe cake washed with n-heptane
customThe solids were then dried under vacuum overnight at 35-50° C.

Sources & evidence

ORD record: ord-e7dad9cf30624028a826500fb508dfbf
Source dataset: uspto-grants-2014_11
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08895603B2

Reaction notes

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