Structural study of histamine H2-receptor antagonists. Five 3-[2-(diamino-methyleneamino)-4-thiazolylmethylthio]propionamidine and -amide derivatives.

(1) N2-Cyano-3-[2-(diaminomethyleneamino)-4- thiazolylmethylthio]propionamidine monohydrate, C9H13N7S2.H2O, Mr = 301.39, P1, a = 11.089 (4), b = 9.130 (6), c = 7.033 (5) A, alpha = 100.99 (6), beta = 83.86 (5), gamma = 86.80 (7) degrees, V = 692.9 (6) A3, Z = 2, Dm = 1.443 (2), Dx = 1.444 g cm-3, lambda(Cu K alpha) = 1.5418 A, mu = 34.86 cm-1, F(000) = 316, T = 293 K, R = 0.043 for 2219 reflections. (2) 3-[2-Diaminomethyleneamino)-4- thiazolylmethylthio]-N2-sulfamoylpropionamidine (famotidine) hydrochloride, C8H15N7O2S3.HCl, Mr = 373.90, Cc, a = 15.205 (3), b = 14.442 (3), c = 9.262 (1) A, beta = 124.00 (5) degrees, V = 1686.1 (7) A3, Z = 4, Dm = 1.470 (2), Dx = 1.473 g cm-3, mu(Cu K alpha) = 56.09 cm-1, F(000) = 776, T = 293 K, R = 0.036 for 1411 reflections. (3) 3-[2-(Diaminomethyleneamino)-4-thiazolylmethylthio]-propi ona mide, C8H13N5OS2, Mr = 259.35, P2(1)2(1)2(1), a = 5.472 (1), b = 18.260 (5), c = 11.890 (3) A, V = 1188.0 (5) A3, Z = 4, Dm = 1.448 (1), Dx = 1.450 g cm-3, mu(Cu K alpha) = 39.26 cm-1, F(000) = 544, T = 293 K, R = 0.036 for 1260 reflections.(ABSTRACT TRUNCATED AT 250 WORDS)