Gamma-Butyrolactone → 5-(2-hydroxyethyl)-2-thiouracil
Reaction equation
C(OCC)=O.[C:6]1(=[O:11])[O:10][CH2:9][CH2:8][CH2:7]1.[CH3:12]C(C)([O-])C.[K+].[NH2:18][C:19]([NH2:21])=[S:20]>CCOCC.O1CCCC1.CC(O)C>[OH:10][CH2:9][CH2:8][C:7]1[C:6](=[O:11])[NH:18][C:19](=[S:20])[NH:21][CH:12]=1Participants
Procedure
A solution of ethyl formate (33.1 ml, 2.1 equiv) and γ-butyrolactone (15 ml, 1 equiv) in ether (400 ml) was added dropwise with stirring to a solution of potassium t-butoxide (52.5 g, 2.4 equiv) in tetrahydrofuran (400 ml). The mixture was allowed to warm to room temperature, and stirred overnight. The solvent was removed in vacuo, 2-propanol (600 ml) and thiourea (29.7 g, 2 equiv) were added, and the mixture was heated to reflux for 5 h. After cooling to room temperature, the precipitate was filtered off, dissolved in water (500 ml), and washed twice with ether. The aqueous solution was acidified to pH5.5 with acetic acid, and the resulting precipitate was filtered off, washed thoroughly with water, and dried in vacuo; yield 23.85 g. 1H-NMR (d6-DMSO) δ 2.36 (2H,t), 3.47 (2H,m), 4.57 (1H,m), 7.24 (1H,s), 12.2 & 12.4 (each 1H, br s); MS (APCI−) found (M−H)=171; C6H8N2O2S requires 172.
Workup
- additionwere added
- temperaturethe mixture was heated
- temperatureto reflux for 5 h
- temperatureAfter cooling to room temperature
- filtrationthe precipitate was filtered off
- dissolutiondissolved in water (500 ml)
- washwashed twice with ether
- filtrationthe resulting precipitate was filtered off
- washwashed thoroughly with water
- customdried in vacuo
Sources & evidence
- ORD record
- ord-712b989dc47044dea3e9dd66e9835713
- Source dataset
- uspto-grants-2016_02
- Patent number
- US09266841B2
Reaction notes
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