Sulfuryl chloride → 2,6-dichloro-7-chloromethyl-5H-thiazolo[3,2-a]pyrimidine-5-one

HRID 326151Notes

Reaction equation

HRID 326151 reaction equation
[Cl:1][C:2]1[S:13][C:5]2=[N:6][C:7]([CH2:11][Cl:12])=[CH:8][C:9](=[O:10])[N:4]2[CH:3]=1.S(Cl)([Cl:17])(=O)=O.C([O-])(O)=O.[Na+]>ClC(Cl)C>[Cl:1][C:2]1[S:13][C:5]2=[N:6][C:7]([CH2:11][Cl:12])=[C:8]([Cl:17])[C:9](=[O:10])[N:4]2[CH:3]=1

Participants

5

Reactant 3

HCID 24648Sulfuryl chlorideHCID 516892Sodium BicarbonateHCID 131058502-chloro-7-chloromethyl-5H-thiazolo[3,2-a]pyrimidine-5-one

Product 1

HCID 131058622,6-dichloro-7-chloromethyl-5H-thiazolo[3,2-a]pyrimidine-5-oneYield 80.5%

Reagents, catalysts & solvents 1

HCID 63651,1-DichloroethaneSolvent

Procedure

2-chloro-7-chloromethyl-5H-thiazolo[3,2-a]pyrimidine-5-one, (6.07 g), prepared according to Example 5, was reacted with sulfuryl chloride (3.8 g) in dichloroethane (150 ml) under stirring at room temperature for 4 hours. The reaction mixture was treated with 5% aqueous NaHCO3 solution then the organic phase was separated and evaporated in vacuo to dryness. Crystallization from methanol gave 5.6 g of 2,6-dichloro-7-chloromethyl-5H-thiazolo[3,2-a]pyrimidine-5-one, m.p. 117°-119° C. dec., which was reacted with triphenylphosphine (5.95 g) in acetonitrile (115 ml) at the reflux temperature for 20 hours. The solution was evaporated in vacuo to dryness and the residue was purified with isopropyl ether to give 10.4 g of [2,6-dichloro-5H-thiazolo[3,2-a]pyrimidine-5-one-7-yl]-methyl-triphenylphosphonium chloride, which was suspended in dimethylsulfoxide (50 ml) and treated with potassium tert-butoxide (2.41 g) dissolved in dimethylsulfoxide (45 ml) at room temperature.

Workup

  1. customthe organic phase was separated
  2. customevaporated in vacuo to dryness
  3. customCrystallization from methanol

Sources & evidence

ORD record
ord-6fbbb7d4402e474ba0da6ec5e7ff0cd1
Source dataset
uspto-grants-1984_04
Patent number
US04444773

Reaction notes

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