Dimethylformamide → HCID 178479708, compound

3.7 g (10 mmoles) of benzyloxycarbonyl-L-prolyl-p-nitrophenyl ester (Goodman and Stueben: J. Am. Chem. Soc., 81, 3980, 1959) are dissolved in a mixture of 10 ml of dimethylformamide and 5 ml of pyridine, 2.03 g (10 mmoles) of agmatine-dichlorohydrate (in formula II A represents an H2N--C(NH)-- residue, B a chlorine atom and n=2) and 1.4 ml (10 mmoles) of triethylamine added, and stirred for 16 to 20 hours. The reaction mixture is evaporated at reduced pressure. The residue is dissolved in a mixture of 50 ml of 0.1 N hydrochloric acid and 20 ml of ethyl acetate, the aqueous layer is extracted twice with 20 ml of diethyl ether, neutralized with solid sodium hydrogen carbonate and then extracted five times with 20 ml of chloroform. The combined chloroform layers are washed twice with water and evaporated at reduced pressure. The evaporation residue, benzyloxycarbonyl-L-prolyl-agmatine-hydrochloride (RF3 0.32 to 0.42), is dissolved in 40 ml of methanol, 10 ml of 1 N hydrochloric acid added, and the mixture hydrogenated in the presence of palladium charcoal. When the reaction is concluded, the catalyst is filtered, washed with water, and the filtrate evaporated at reduced pressure. The evaporation residue is worked up with diethyl ether, filtered, washed with diethyl ether and dried over potassium hydroxide at reduced pressure. Yield: 2.1 g (70 percent) of the named compound. M.p.: 186° to 189° C.; RF4 0.15 to 0.25; [α]D20 =-33.25° (c=1, methanol).

1. additionadded
2. customThe reaction mixture is evaporated at reduced pressure
3. dissolutionThe residue is dissolved in a mixture of 50 ml of 0.1 N hydrochloric acid and 20 ml of ethyl acetate
4. extractionthe aqueous layer is extracted twice with 20 ml of diethyl ether
5. extractionextracted five times with 20 ml of chloroform
6. washThe combined chloroform layers are washed twice with water
7. customevaporated at reduced pressure
8. dissolutionThe evaporation residue, benzyloxycarbonyl-L-prolyl-agmatine-hydrochloride (RF3 0.32 to 0.42), is dissolved in 40 ml of methanol
9. addition10 ml of 1 N hydrochloric acid added
10. filtrationthe catalyst is filtered
11. washwashed with water
12. customthe filtrate evaporated at reduced pressure
13. filtrationfiltered
14. washwashed with diethyl ether
15. dry with materialdried over potassium hydroxide at reduced pressure
16. custom[α]D20 =-33.25° (c=1, methanol)

ORD record

ord-5b352f40f8344c4c938ddc24c860cb7f

Source dataset

uspto-grants-1982_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04346078