diff --git a/sympy/core/expr.py b/sympy/core/expr.py
index 88713b6..44eda0c 100644
--- a/sympy/core/expr.py
+++ b/sympy/core/expr.py
@@ -1825,7 +1825,7 @@ def as_coeff_exponent(self, x):
         """ c*x**e -> c,e where x can be any symbolic expression.
         """
         x = sympify(x)
-        wc = Wild('wc')
+        wc = Wild('wc', exclude=[x])
         we = Wild('we')
         p  = wc*x**we
         from sympy import collect
diff --git a/sympy/core/mul.py b/sympy/core/mul.py
index d544ca4..ef27545 100644
--- a/sympy/core/mul.py
+++ b/sympy/core/mul.py
@@ -3,7 +3,8 @@
 from operations import AssocOp
 from cache import cacheit
 from logic import fuzzy_not
-from compatibility import cmp_to_key
+
+from sympy.utilities.misc import default_sort_key

 # internal marker to indicate:
 #   "there are still non-commutative objects -- don't forget to process them"
@@ -452,7 +453,7 @@ def flatten(cls, seq):
             return [coeff], [], order_symbols

         # order commutative part canonically
-        c_part.sort(key=cmp_to_key(Basic.compare))
+        c_part.sort(key=default_sort_key)

         # current code expects coeff to be always in slot-0
         if coeff is not S.One: