Sulfuric Acid → Methyl 3-thioureidobenzoate

HRID 882783Notes

Reaction equation

S(=O)(=O)(O)O.[NH2:6][C:7]1[CH:8]=[C:9]([CH:14]=[CH:15][CH:16]=1)[C:10]([O:12][CH3:13])=[O:11].[S-:17][C:18]#[N:19].[K+].C1OCCOCCOCCOCCOCCOC1>ClC1C=CC=CC=1>[CH3:13][O:12][C:10](=[O:11])[C:9]1[CH:14]=[CH:15][CH:16]=[C:7]([NH:6][C:18]([NH2:19])=[S:17])[CH:8]=1

Participants

Conditions

Temperature: 100 °C

Procedure

At −10° C. sulfuric acid (0.46 mL) is added dropwise to a solution of methyl 3-aminobenzoate (17.2 mmol) in chlorobenzene (19 mL). After 15 min potassium thiocyanate (18.2 mmol) is added portionwise over 30 min. The mixture is treated with 18-crown-6 (0.18 mmol), heated to 100° C. for 16 h and allowed to cool to rt. After 4 h the obtained precipitate is filtered off and washed successively with chlorobenzene (33 mL) and hexane (three times 130 mL). The residue is diluted with water (390 mL) and the suspension is stirred for 30 min. After filtration the residue is washed twice with water (130 ml, each), concentrated in vacuo and dried additionally by azeotropic removal of water with toluene. The obtained product is used without further purification. LC-MS: tR=0.66 min; [M+H]+=211.0.

Workup

temperatureto cool to rt
filtrationAfter 4 h the obtained precipitate is filtered off
washwashed successively with chlorobenzene (33 mL) and hexane (three times 130 mL)
additionThe residue is diluted with water (390 mL)
filtrationAfter filtration the residue
washis washed twice with water (130 ml
concentrationeach), concentrated in vacuo
dry with materialdried additionally by azeotropic removal of water with toluene
customThe obtained product is used without further purification

Sources & evidence

ORD record: ord-7c42796eb5464a3b9d1c736d25bd721f
Source dataset: uspto-grants-2012_08
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08236801B2

Reaction notes

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