abstract |
Title cpds. are of formula (I): (where n is 0-5; Y is halogen, alkyl, alkoxy; A is alkane deriv.; X is O or S; R1 is aryl; R2 is H or hydrocarbon radical; R3 is a hydrocarbon radical). Cpds. (I; R2 is H), are prepd. by reacting with an acid, alcohol, mercaptan, phenol or thiophenol at 20 degrees C, pref. -25 degrees to -5 degrees C. |