| abstract |
1404469 Peptide derivatives of penicillanic acids PFIZER Inc 11 Sept 1972 [16 May 1972] 42179/72 Heading C3H [Also in Division C2] Per se compounds of formula wherein Ar is phenyl, 4-hydroxyphenyl, 2- thienyl or 3-thienyl; A is alkylene or alkylidener, n is 1-3; R 1 , R 2 , R 3 and R 4 are each H or alkyl, or R 1 and R 4 , R 2 and R 4 , R 2 and R 3 taken together are alkylene. The following intermediates are prepared: 3 - guanyl - 1 - ureidoacetylglycylglycine hydrochloride by the reaction of glycylglycylglycine with 3 - guanyl - 1 - nitrourea, followed by treatment with hydrogen chloride gas. Peptide intermediates of formula are prepared by the reaction of the appropriate dipeptide or tripeptide with (1)-(7) the requisite 3-guanyl-1-nitrourea (8)-(9) the requisite guanylureidoalkanoyl chloride; the substituents beingn[GB1404469A] |