Lawesson's reagent → 3-(Benzyloxy)-N,9,9-trimethyl-4-oxo-4,6,7,9-tetrahydropyrimido[2,1-c][1,4]oxazine-2-carbothioamide

HRID 390336Notes

Reaction equation

[CH2:1]([O:8][C:9]1[C:18](=[O:19])[N:17]2[C:12]([C:13]([CH3:21])([CH3:20])[O:14][CH2:15][CH2:16]2)=[N:11][C:10]=1[C:22]([NH:24][CH3:25])=O)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.COC1C=CC(P2(SP(C3C=CC(OC)=CC=3)(=S)S2)=[S:35])=CC=1>C1COCC1>[CH2:1]([O:8][C:9]1[C:18](=[O:19])[N:17]2[C:12]([C:13]([CH3:21])([CH3:20])[O:14][CH2:15][CH2:16]2)=[N:11][C:10]=1[C:22](=[S:35])[NH:24][CH3:25])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1

Participants

Conditions

Temperature: 50 °C

Procedure

To a solution of 3-(benzyloxy)-N,9,9-trimethyl-4-oxo-4,6,7,9-tetrahydropyrimido[2,1-c][1,4]oxazine-2-carboxamide (0.40 g, 1.17 mmol, 1.0 equiv) in THF (12 mL) under a nitrogen atmosphere, was added Lawesson's reagent (0.28 g, 0.70 mmol, 0.6 equiv). The yellow solution was then heated to 50° C. (oil bath). After stirring for 1 h, the reaction was cooled to ambient temperature and concentrated in vacuo. The crude product was purified by silica gel chromatography (20-100% ethyl acetate/hexane) to provide the title compound (0.38 g, 90% yield) as a yellow solid. 1H NMR (400 MHz, CDCl3) δ ppm 8.19 (s, 1H), 7.45-7.57 (m, 2H), 7.29-7.42 (m, 3H), 5.25 (s, 2H), 3.93-4.12 (m, 4H), 3.17 (d, J=5.04 Hz, 3H), 1.62 (s, 6H); LCMS (ES+, (M+H)+) m/z 360.19.

Workup

temperaturethe reaction was cooled to ambient temperature
concentrationconcentrated in vacuo
customThe crude product was purified by silica gel chromatography (20-100% ethyl acetate/hexane)

Sources & evidence

ORD record: ord-1ba8d93c0d26413585a9c093e04acd1b
Source dataset: uspto-grants-2013_02
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08383639B2

Reaction notes

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