Camptothecin → (R)-4-Ethyl-1H-pyrano(3',4':6,7)indolizino(1,2-b)quinoline-3,14(4H,12H)-dione

HRID 636829Notes

Reaction equation

[CH3:1][CH2:2][C@@:3]1(O)[C:8](=[O:9])[O:7][CH2:6][C:5]2[C:10]([N:12]3[C:24](=[CH:25][C:4]1=2)[C:23]1[N:22]=[C:21]2[C:16]([CH:17]=[CH:18][CH:19]=[CH:20]2)=[CH:15][C:14]=1[CH2:13]3)=[O:11]>O1CCOCC1>[CH3:1][CH2:2][C@H:3]1[C:8](=[O:9])[O:7][CH2:6][C:5]2[C:10]([N:12]3[C:24](=[CH:25][C:4]1=2)[C:23]1[C:14](=[CH:15][C:16]2[C:21]([N:22]=1)=[CH:20][CH:19]=[CH:18][CH:17]=2)[CH2:13]3)=[O:11]

Participants

Conditions

Temperature: 90 °C

Procedure

Camptothecin (500 mg, 1.44 mmol) was suspended in 1,4-dioxane (10 mL) and added Lawsson's reagent (290.5 mg, 0.72 mmol). The reaction mixture was then heated to 90° C. for 10 hours under an inert atmosphere. The resultant homogeneous reaction mixture was then concentrated, organic portion was taken up in chloroform (25 mL) and the aqueous fraction was repeatedly extracted with chloroform (25 mL×3). The combined organic portion was then concentrated to get the title compound in the crude form. The crude product was then flash chromatographed over a bed of florisil using 10% chloroform in methanol to furnish the desired product in 40% yield in diastereomeric mixture.

Workup

concentrationThe resultant homogeneous reaction mixture was then concentrated
extractionthe aqueous fraction was repeatedly extracted with chloroform (25 mL×3)
concentrationThe combined organic portion was then concentrated

Sources & evidence

ORD record: ord-5d25f067f40a4c70bbeee929d867e54e
Source dataset: uspto-grants-2001_02
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06194579B1

Reaction notes

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