Water → (2-trityl-2H-tetrazol-5-yl)-acetic acid

To a mixture of (2H-tetrazol-5-yl)-acetic acid ethyl ester (2.0 g, 12.81 mmol), trityl chloride (3.7 g, 13.45 mmol) in dry THF (75 ml) was added TEA (3.7 ml). The resulting mixture was stirred for 18 hrs. at room temperature. Water (10 ml) was added and the precipitate filtered off, redissolved in EtOAc (25 ml) and washed with saturated aqueous ammonium chloride (2×15 ml). The organic phase was dried (Na2SO4), filtered and evaporated in vacuo. The residue was suspended in ethanol (150 ml) and potassium hydroxide (0.8 g, 13.45 mmol) dissolved in ethanol (100 ml) was added. The resulting mixture was stirred for 18 hrs. at room temperature. The precipitate was filtered off and dissolved in water (150 ml) and acidified with conc. HCl (use diluted HCl). The precipitate was filtered off and washed with diethyl ether and dried in vacuo at 50° C. affording 0.7 g (15%) of (2-trityl-2H-tetrazol-5-yl)-acetic acid as a solid.

1. customat room temperature
2. filtrationthe precipitate filtered off
3. dissolutionredissolved in EtOAc (25 ml)
4. washwashed with saturated aqueous ammonium chloride (2×15 ml)
5. dry with materialThe organic phase was dried (Na2SO4)
6. filtrationfiltered
7. customevaporated in vacuo
8. additionwas added
9. stirringThe resulting mixture was stirred for 18 hrs
10. customat room temperature
11. filtrationThe precipitate was filtered off
12. dissolutiondissolved in water (150 ml)
13. filtrationThe precipitate was filtered off
14. washwashed with diethyl ether
15. customdried in vacuo at 50° C.

ORD record

ord-05975c441f664452ac0030753f29e77e

Source dataset

uspto-grants-2010_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07700583B2