HCID 20068714, compound → HCID 136027785, compound

A mixture of 2.25 g of 2-ethyl-4-hydroxydihydrothieno[3,2-d]pyrimidine and 2-ethyl-4-hydroxydihydrothieno[3,4-d]pyrimidine in phosphorus oxychloride (50 ml) was refluxed for 2 hours then cooled and concentrated under vacuum. The residue was dissolved in chloroform and poured into ice water. The mixture was basified with ammonia. The layers were separated and the aqueous phase extracted with chloroform. The combined organic extracts were washed with brine, dried (MgSO4) and concentrated. The residual orange oil was chromatographed on 140 g of silica eluting with ethyl acetate/hexane (1/4). Concentration of the first product fractions gave an oil, 1.05 g, shown by NMR to be 4-chloro-2-ethyldihydrothieno[3,4-d]pyrimidine. Concentration of the second product fractions gave an oil, 1.05 g, shown by NMR to be 4-chloro-2-ethyl-dihydrothieno-[3,2 d]pyrimidine.

1. temperaturewas refluxed for 2 hours
2. temperaturethen cooled
3. concentrationconcentrated under vacuum
4. dissolutionThe residue was dissolved in chloroform
5. additionpoured into ice water
6. customThe layers were separated
7. extractionthe aqueous phase extracted with chloroform
8. washThe combined organic extracts were washed with brine
9. dry with materialdried (MgSO4)
10. concentrationconcentrated
11. customThe residual orange oil was chromatographed on 140 g of silica eluting with ethyl acetate/hexane (1/4)
12. customConcentration of the first product fractions gave an oil, 1.05 g
13. customConcentration of the second product fractions gave an oil, 1.05 g

ORD record

ord-c8ccb6de207f4e589e5d973fd958b46a

Source dataset

uspto-grants-1991_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04994464